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Commit | Line | Data |
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9f27ee59 JF |
1 | /* |
2 | * blkfront.c | |
3 | * | |
4 | * XenLinux virtual block device driver. | |
5 | * | |
6 | * Copyright (c) 2003-2004, Keir Fraser & Steve Hand | |
7 | * Modifications by Mark A. Williamson are (c) Intel Research Cambridge | |
8 | * Copyright (c) 2004, Christian Limpach | |
9 | * Copyright (c) 2004, Andrew Warfield | |
10 | * Copyright (c) 2005, Christopher Clark | |
11 | * Copyright (c) 2005, XenSource Ltd | |
12 | * | |
13 | * This program is free software; you can redistribute it and/or | |
14 | * modify it under the terms of the GNU General Public License version 2 | |
15 | * as published by the Free Software Foundation; or, when distributed | |
16 | * separately from the Linux kernel or incorporated into other | |
17 | * software packages, subject to the following license: | |
18 | * | |
19 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
20 | * of this source file (the "Software"), to deal in the Software without | |
21 | * restriction, including without limitation the rights to use, copy, modify, | |
22 | * merge, publish, distribute, sublicense, and/or sell copies of the Software, | |
23 | * and to permit persons to whom the Software is furnished to do so, subject to | |
24 | * the following conditions: | |
25 | * | |
26 | * The above copyright notice and this permission notice shall be included in | |
27 | * all copies or substantial portions of the Software. | |
28 | * | |
29 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
30 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
31 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
32 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
33 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | |
34 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS | |
35 | * IN THE SOFTWARE. | |
36 | */ | |
37 | ||
38 | #include <linux/interrupt.h> | |
39 | #include <linux/blkdev.h> | |
907c3eb1 | 40 | #include <linux/blk-mq.h> |
597592d9 | 41 | #include <linux/hdreg.h> |
440a01a7 | 42 | #include <linux/cdrom.h> |
9f27ee59 | 43 | #include <linux/module.h> |
5a0e3ad6 | 44 | #include <linux/slab.h> |
2a48fc0a | 45 | #include <linux/mutex.h> |
9e973e64 | 46 | #include <linux/scatterlist.h> |
34ae2e47 | 47 | #include <linux/bitmap.h> |
155b7edb | 48 | #include <linux/list.h> |
9f27ee59 | 49 | |
1ccbf534 | 50 | #include <xen/xen.h> |
9f27ee59 JF |
51 | #include <xen/xenbus.h> |
52 | #include <xen/grant_table.h> | |
53 | #include <xen/events.h> | |
54 | #include <xen/page.h> | |
c1c5413a | 55 | #include <xen/platform_pci.h> |
9f27ee59 JF |
56 | |
57 | #include <xen/interface/grant_table.h> | |
58 | #include <xen/interface/io/blkif.h> | |
3e334239 | 59 | #include <xen/interface/io/protocols.h> |
9f27ee59 JF |
60 | |
61 | #include <asm/xen/hypervisor.h> | |
62 | ||
63 | enum blkif_state { | |
64 | BLKIF_STATE_DISCONNECTED, | |
65 | BLKIF_STATE_CONNECTED, | |
66 | BLKIF_STATE_SUSPENDED, | |
67 | }; | |
68 | ||
0a8704a5 RPM |
69 | struct grant { |
70 | grant_ref_t gref; | |
a7a6df22 | 71 | struct page *page; |
155b7edb | 72 | struct list_head node; |
0a8704a5 RPM |
73 | }; |
74 | ||
9f27ee59 JF |
75 | struct blk_shadow { |
76 | struct blkif_request req; | |
a945b980 | 77 | struct request *request; |
402b27f9 RPM |
78 | struct grant **grants_used; |
79 | struct grant **indirect_grants; | |
b7649158 | 80 | struct scatterlist *sg; |
402b27f9 RPM |
81 | }; |
82 | ||
83 | struct split_bio { | |
84 | struct bio *bio; | |
85 | atomic_t pending; | |
9f27ee59 JF |
86 | }; |
87 | ||
2a48fc0a | 88 | static DEFINE_MUTEX(blkfront_mutex); |
83d5cde4 | 89 | static const struct block_device_operations xlvbd_block_fops; |
9f27ee59 | 90 | |
402b27f9 RPM |
91 | /* |
92 | * Maximum number of segments in indirect requests, the actual value used by | |
93 | * the frontend driver is the minimum of this value and the value provided | |
94 | * by the backend driver. | |
95 | */ | |
96 | ||
97 | static unsigned int xen_blkif_max_segments = 32; | |
2d5dc3ba KRW |
98 | module_param_named(max, xen_blkif_max_segments, int, S_IRUGO); |
99 | MODULE_PARM_DESC(max, "Maximum amount of segments in indirect requests (default is 32)"); | |
402b27f9 | 100 | |
86839c56 BL |
101 | /* |
102 | * Maximum order of pages to be used for the shared ring between front and | |
103 | * backend, 4KB page granularity is used. | |
104 | */ | |
105 | static unsigned int xen_blkif_max_ring_order; | |
106 | module_param_named(max_ring_page_order, xen_blkif_max_ring_order, int, S_IRUGO); | |
107 | MODULE_PARM_DESC(max_ring_page_order, "Maximum order of pages to be used for the shared ring"); | |
108 | ||
109 | #define BLK_RING_SIZE(info) __CONST_RING_SIZE(blkif, PAGE_SIZE * (info)->nr_ring_pages) | |
110 | #define BLK_MAX_RING_SIZE __CONST_RING_SIZE(blkif, PAGE_SIZE * XENBUS_MAX_RING_PAGES) | |
111 | /* | |
112 | * ring-ref%i i=(-1UL) would take 11 characters + 'ring-ref' is 8, so 19 | |
113 | * characters are enough. Define to 20 to keep consist with backend. | |
114 | */ | |
115 | #define RINGREF_NAME_LEN (20) | |
9f27ee59 JF |
116 | |
117 | /* | |
118 | * We have one of these per vbd, whether ide, scsi or 'other'. They | |
119 | * hang in private_data off the gendisk structure. We may end up | |
120 | * putting all kinds of interesting stuff here :-) | |
121 | */ | |
122 | struct blkfront_info | |
123 | { | |
3467811e | 124 | spinlock_t io_lock; |
b70f5fa0 | 125 | struct mutex mutex; |
9f27ee59 | 126 | struct xenbus_device *xbdev; |
9f27ee59 JF |
127 | struct gendisk *gd; |
128 | int vdevice; | |
129 | blkif_vdev_t handle; | |
130 | enum blkif_state connected; | |
86839c56 BL |
131 | int ring_ref[XENBUS_MAX_RING_PAGES]; |
132 | unsigned int nr_ring_pages; | |
9f27ee59 JF |
133 | struct blkif_front_ring ring; |
134 | unsigned int evtchn, irq; | |
135 | struct request_queue *rq; | |
136 | struct work_struct work; | |
137 | struct gnttab_free_callback callback; | |
86839c56 | 138 | struct blk_shadow shadow[BLK_MAX_RING_SIZE]; |
bfe11d6d RPM |
139 | struct list_head grants; |
140 | struct list_head indirect_pages; | |
0a8704a5 | 141 | unsigned int persistent_gnts_c; |
9f27ee59 | 142 | unsigned long shadow_free; |
4913efe4 | 143 | unsigned int feature_flush; |
5ea42986 KRW |
144 | unsigned int feature_discard:1; |
145 | unsigned int feature_secdiscard:1; | |
ed30bf31 LD |
146 | unsigned int discard_granularity; |
147 | unsigned int discard_alignment; | |
0a8704a5 | 148 | unsigned int feature_persistent:1; |
402b27f9 | 149 | unsigned int max_indirect_segments; |
1d78d705 | 150 | int is_ready; |
907c3eb1 | 151 | struct blk_mq_tag_set tag_set; |
9f27ee59 JF |
152 | }; |
153 | ||
0e345826 JB |
154 | static unsigned int nr_minors; |
155 | static unsigned long *minors; | |
156 | static DEFINE_SPINLOCK(minor_lock); | |
157 | ||
9f27ee59 JF |
158 | #define GRANT_INVALID_REF 0 |
159 | ||
160 | #define PARTS_PER_DISK 16 | |
9246b5f0 | 161 | #define PARTS_PER_EXT_DISK 256 |
9f27ee59 JF |
162 | |
163 | #define BLKIF_MAJOR(dev) ((dev)>>8) | |
164 | #define BLKIF_MINOR(dev) ((dev) & 0xff) | |
165 | ||
9246b5f0 CL |
166 | #define EXT_SHIFT 28 |
167 | #define EXTENDED (1<<EXT_SHIFT) | |
168 | #define VDEV_IS_EXTENDED(dev) ((dev)&(EXTENDED)) | |
169 | #define BLKIF_MINOR_EXT(dev) ((dev)&(~EXTENDED)) | |
c80a4209 SS |
170 | #define EMULATED_HD_DISK_MINOR_OFFSET (0) |
171 | #define EMULATED_HD_DISK_NAME_OFFSET (EMULATED_HD_DISK_MINOR_OFFSET / 256) | |
196cfe2a SB |
172 | #define EMULATED_SD_DISK_MINOR_OFFSET (0) |
173 | #define EMULATED_SD_DISK_NAME_OFFSET (EMULATED_SD_DISK_MINOR_OFFSET / 256) | |
9f27ee59 | 174 | |
9246b5f0 | 175 | #define DEV_NAME "xvd" /* name in /dev */ |
9f27ee59 | 176 | |
402b27f9 | 177 | #define SEGS_PER_INDIRECT_FRAME \ |
80bfa2f6 | 178 | (PAGE_SIZE/sizeof(struct blkif_request_segment)) |
402b27f9 RPM |
179 | #define INDIRECT_GREFS(_segs) \ |
180 | ((_segs + SEGS_PER_INDIRECT_FRAME - 1)/SEGS_PER_INDIRECT_FRAME) | |
181 | ||
182 | static int blkfront_setup_indirect(struct blkfront_info *info); | |
d50babbe | 183 | static int blkfront_gather_backend_features(struct blkfront_info *info); |
402b27f9 | 184 | |
9f27ee59 JF |
185 | static int get_id_from_freelist(struct blkfront_info *info) |
186 | { | |
187 | unsigned long free = info->shadow_free; | |
86839c56 | 188 | BUG_ON(free >= BLK_RING_SIZE(info)); |
97e36834 KRW |
189 | info->shadow_free = info->shadow[free].req.u.rw.id; |
190 | info->shadow[free].req.u.rw.id = 0x0fffffee; /* debug */ | |
9f27ee59 JF |
191 | return free; |
192 | } | |
193 | ||
6878c32e | 194 | static int add_id_to_freelist(struct blkfront_info *info, |
9f27ee59 JF |
195 | unsigned long id) |
196 | { | |
6878c32e KRW |
197 | if (info->shadow[id].req.u.rw.id != id) |
198 | return -EINVAL; | |
199 | if (info->shadow[id].request == NULL) | |
200 | return -EINVAL; | |
97e36834 | 201 | info->shadow[id].req.u.rw.id = info->shadow_free; |
a945b980 | 202 | info->shadow[id].request = NULL; |
9f27ee59 | 203 | info->shadow_free = id; |
6878c32e | 204 | return 0; |
9f27ee59 JF |
205 | } |
206 | ||
9c1e050c RPM |
207 | static int fill_grant_buffer(struct blkfront_info *info, int num) |
208 | { | |
209 | struct page *granted_page; | |
210 | struct grant *gnt_list_entry, *n; | |
211 | int i = 0; | |
212 | ||
213 | while(i < num) { | |
214 | gnt_list_entry = kzalloc(sizeof(struct grant), GFP_NOIO); | |
215 | if (!gnt_list_entry) | |
216 | goto out_of_memory; | |
217 | ||
bfe11d6d RPM |
218 | if (info->feature_persistent) { |
219 | granted_page = alloc_page(GFP_NOIO); | |
220 | if (!granted_page) { | |
221 | kfree(gnt_list_entry); | |
222 | goto out_of_memory; | |
223 | } | |
a7a6df22 | 224 | gnt_list_entry->page = granted_page; |
9c1e050c RPM |
225 | } |
226 | ||
9c1e050c | 227 | gnt_list_entry->gref = GRANT_INVALID_REF; |
bfe11d6d | 228 | list_add(&gnt_list_entry->node, &info->grants); |
9c1e050c RPM |
229 | i++; |
230 | } | |
231 | ||
232 | return 0; | |
233 | ||
234 | out_of_memory: | |
235 | list_for_each_entry_safe(gnt_list_entry, n, | |
bfe11d6d | 236 | &info->grants, node) { |
9c1e050c | 237 | list_del(&gnt_list_entry->node); |
bfe11d6d | 238 | if (info->feature_persistent) |
a7a6df22 | 239 | __free_page(gnt_list_entry->page); |
9c1e050c RPM |
240 | kfree(gnt_list_entry); |
241 | i--; | |
242 | } | |
243 | BUG_ON(i != 0); | |
244 | return -ENOMEM; | |
245 | } | |
246 | ||
4f503fbd | 247 | static struct grant *get_free_grant(struct blkfront_info *info) |
9c1e050c RPM |
248 | { |
249 | struct grant *gnt_list_entry; | |
9c1e050c | 250 | |
bfe11d6d RPM |
251 | BUG_ON(list_empty(&info->grants)); |
252 | gnt_list_entry = list_first_entry(&info->grants, struct grant, | |
4f503fbd | 253 | node); |
9c1e050c RPM |
254 | list_del(&gnt_list_entry->node); |
255 | ||
4f503fbd | 256 | if (gnt_list_entry->gref != GRANT_INVALID_REF) |
9c1e050c | 257 | info->persistent_gnts_c--; |
4f503fbd JG |
258 | |
259 | return gnt_list_entry; | |
260 | } | |
261 | ||
262 | static inline void grant_foreign_access(const struct grant *gnt_list_entry, | |
263 | const struct blkfront_info *info) | |
264 | { | |
265 | gnttab_page_grant_foreign_access_ref_one(gnt_list_entry->gref, | |
266 | info->xbdev->otherend_id, | |
267 | gnt_list_entry->page, | |
268 | 0); | |
269 | } | |
270 | ||
271 | static struct grant *get_grant(grant_ref_t *gref_head, | |
272 | unsigned long gfn, | |
273 | struct blkfront_info *info) | |
274 | { | |
275 | struct grant *gnt_list_entry = get_free_grant(info); | |
276 | ||
277 | if (gnt_list_entry->gref != GRANT_INVALID_REF) | |
9c1e050c | 278 | return gnt_list_entry; |
4f503fbd JG |
279 | |
280 | /* Assign a gref to this page */ | |
281 | gnt_list_entry->gref = gnttab_claim_grant_reference(gref_head); | |
282 | BUG_ON(gnt_list_entry->gref == -ENOSPC); | |
283 | if (info->feature_persistent) | |
284 | grant_foreign_access(gnt_list_entry, info); | |
285 | else { | |
286 | /* Grant access to the GFN passed by the caller */ | |
287 | gnttab_grant_foreign_access_ref(gnt_list_entry->gref, | |
288 | info->xbdev->otherend_id, | |
289 | gfn, 0); | |
9c1e050c RPM |
290 | } |
291 | ||
4f503fbd JG |
292 | return gnt_list_entry; |
293 | } | |
294 | ||
295 | static struct grant *get_indirect_grant(grant_ref_t *gref_head, | |
296 | struct blkfront_info *info) | |
297 | { | |
298 | struct grant *gnt_list_entry = get_free_grant(info); | |
299 | ||
300 | if (gnt_list_entry->gref != GRANT_INVALID_REF) | |
301 | return gnt_list_entry; | |
302 | ||
9c1e050c RPM |
303 | /* Assign a gref to this page */ |
304 | gnt_list_entry->gref = gnttab_claim_grant_reference(gref_head); | |
305 | BUG_ON(gnt_list_entry->gref == -ENOSPC); | |
bfe11d6d | 306 | if (!info->feature_persistent) { |
4f503fbd JG |
307 | struct page *indirect_page; |
308 | ||
309 | /* Fetch a pre-allocated page to use for indirect grefs */ | |
310 | BUG_ON(list_empty(&info->indirect_pages)); | |
311 | indirect_page = list_first_entry(&info->indirect_pages, | |
312 | struct page, lru); | |
313 | list_del(&indirect_page->lru); | |
314 | gnt_list_entry->page = indirect_page; | |
bfe11d6d | 315 | } |
4f503fbd JG |
316 | grant_foreign_access(gnt_list_entry, info); |
317 | ||
9c1e050c RPM |
318 | return gnt_list_entry; |
319 | } | |
320 | ||
6878c32e KRW |
321 | static const char *op_name(int op) |
322 | { | |
323 | static const char *const names[] = { | |
324 | [BLKIF_OP_READ] = "read", | |
325 | [BLKIF_OP_WRITE] = "write", | |
326 | [BLKIF_OP_WRITE_BARRIER] = "barrier", | |
327 | [BLKIF_OP_FLUSH_DISKCACHE] = "flush", | |
328 | [BLKIF_OP_DISCARD] = "discard" }; | |
329 | ||
330 | if (op < 0 || op >= ARRAY_SIZE(names)) | |
331 | return "unknown"; | |
332 | ||
333 | if (!names[op]) | |
334 | return "reserved"; | |
335 | ||
336 | return names[op]; | |
337 | } | |
0e345826 JB |
338 | static int xlbd_reserve_minors(unsigned int minor, unsigned int nr) |
339 | { | |
340 | unsigned int end = minor + nr; | |
341 | int rc; | |
342 | ||
343 | if (end > nr_minors) { | |
344 | unsigned long *bitmap, *old; | |
345 | ||
f094148a | 346 | bitmap = kcalloc(BITS_TO_LONGS(end), sizeof(*bitmap), |
0e345826 JB |
347 | GFP_KERNEL); |
348 | if (bitmap == NULL) | |
349 | return -ENOMEM; | |
350 | ||
351 | spin_lock(&minor_lock); | |
352 | if (end > nr_minors) { | |
353 | old = minors; | |
354 | memcpy(bitmap, minors, | |
355 | BITS_TO_LONGS(nr_minors) * sizeof(*bitmap)); | |
356 | minors = bitmap; | |
357 | nr_minors = BITS_TO_LONGS(end) * BITS_PER_LONG; | |
358 | } else | |
359 | old = bitmap; | |
360 | spin_unlock(&minor_lock); | |
361 | kfree(old); | |
362 | } | |
363 | ||
364 | spin_lock(&minor_lock); | |
365 | if (find_next_bit(minors, end, minor) >= end) { | |
34ae2e47 | 366 | bitmap_set(minors, minor, nr); |
0e345826 JB |
367 | rc = 0; |
368 | } else | |
369 | rc = -EBUSY; | |
370 | spin_unlock(&minor_lock); | |
371 | ||
372 | return rc; | |
373 | } | |
374 | ||
375 | static void xlbd_release_minors(unsigned int minor, unsigned int nr) | |
376 | { | |
377 | unsigned int end = minor + nr; | |
378 | ||
379 | BUG_ON(end > nr_minors); | |
380 | spin_lock(&minor_lock); | |
34ae2e47 | 381 | bitmap_clear(minors, minor, nr); |
0e345826 JB |
382 | spin_unlock(&minor_lock); |
383 | } | |
384 | ||
9f27ee59 JF |
385 | static void blkif_restart_queue_callback(void *arg) |
386 | { | |
387 | struct blkfront_info *info = (struct blkfront_info *)arg; | |
388 | schedule_work(&info->work); | |
389 | } | |
390 | ||
afe42d7d | 391 | static int blkif_getgeo(struct block_device *bd, struct hd_geometry *hg) |
597592d9 IC |
392 | { |
393 | /* We don't have real geometry info, but let's at least return | |
394 | values consistent with the size of the device */ | |
395 | sector_t nsect = get_capacity(bd->bd_disk); | |
396 | sector_t cylinders = nsect; | |
397 | ||
398 | hg->heads = 0xff; | |
399 | hg->sectors = 0x3f; | |
400 | sector_div(cylinders, hg->heads * hg->sectors); | |
401 | hg->cylinders = cylinders; | |
402 | if ((sector_t)(hg->cylinders + 1) * hg->heads * hg->sectors < nsect) | |
403 | hg->cylinders = 0xffff; | |
404 | return 0; | |
405 | } | |
406 | ||
a63c848b | 407 | static int blkif_ioctl(struct block_device *bdev, fmode_t mode, |
62aa0054 | 408 | unsigned command, unsigned long argument) |
440a01a7 | 409 | { |
a63c848b | 410 | struct blkfront_info *info = bdev->bd_disk->private_data; |
440a01a7 CL |
411 | int i; |
412 | ||
413 | dev_dbg(&info->xbdev->dev, "command: 0x%x, argument: 0x%lx\n", | |
414 | command, (long)argument); | |
415 | ||
416 | switch (command) { | |
417 | case CDROMMULTISESSION: | |
418 | dev_dbg(&info->xbdev->dev, "FIXME: support multisession CDs later\n"); | |
419 | for (i = 0; i < sizeof(struct cdrom_multisession); i++) | |
420 | if (put_user(0, (char __user *)(argument + i))) | |
421 | return -EFAULT; | |
422 | return 0; | |
423 | ||
424 | case CDROM_GET_CAPABILITY: { | |
425 | struct gendisk *gd = info->gd; | |
426 | if (gd->flags & GENHD_FL_CD) | |
427 | return 0; | |
428 | return -EINVAL; | |
429 | } | |
430 | ||
431 | default: | |
432 | /*printk(KERN_ALERT "ioctl %08x not supported by Xen blkdev\n", | |
433 | command);*/ | |
434 | return -EINVAL; /* same return as native Linux */ | |
435 | } | |
436 | ||
437 | return 0; | |
438 | } | |
439 | ||
33204663 JG |
440 | static int blkif_queue_discard_req(struct request *req) |
441 | { | |
442 | struct blkfront_info *info = req->rq_disk->private_data; | |
443 | struct blkif_request *ring_req; | |
444 | unsigned long id; | |
445 | ||
446 | /* Fill out a communications ring structure. */ | |
447 | ring_req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt); | |
448 | id = get_id_from_freelist(info); | |
449 | info->shadow[id].request = req; | |
450 | ||
451 | ring_req->operation = BLKIF_OP_DISCARD; | |
452 | ring_req->u.discard.nr_sectors = blk_rq_sectors(req); | |
453 | ring_req->u.discard.id = id; | |
454 | ring_req->u.discard.sector_number = (blkif_sector_t)blk_rq_pos(req); | |
455 | if ((req->cmd_flags & REQ_SECURE) && info->feature_secdiscard) | |
456 | ring_req->u.discard.flag = BLKIF_DISCARD_SECURE; | |
457 | else | |
458 | ring_req->u.discard.flag = 0; | |
459 | ||
460 | info->ring.req_prod_pvt++; | |
461 | ||
462 | /* Keep a private copy so we can reissue requests when recovering. */ | |
463 | info->shadow[id].req = *ring_req; | |
464 | ||
465 | return 0; | |
466 | } | |
467 | ||
468 | static int blkif_queue_rw_req(struct request *req) | |
9f27ee59 JF |
469 | { |
470 | struct blkfront_info *info = req->rq_disk->private_data; | |
9f27ee59 | 471 | struct blkif_request *ring_req; |
9f27ee59 JF |
472 | unsigned long id; |
473 | unsigned int fsect, lsect; | |
402b27f9 | 474 | int i, ref, n; |
80bfa2f6 | 475 | struct blkif_request_segment *segments = NULL; |
0a8704a5 RPM |
476 | |
477 | /* | |
478 | * Used to store if we are able to queue the request by just using | |
479 | * existing persistent grants, or if we have to get new grants, | |
480 | * as there are not sufficiently many free. | |
481 | */ | |
482 | bool new_persistent_gnts; | |
9f27ee59 | 483 | grant_ref_t gref_head; |
0a8704a5 | 484 | struct grant *gnt_list_entry = NULL; |
9e973e64 | 485 | struct scatterlist *sg; |
402b27f9 | 486 | int nseg, max_grefs; |
9f27ee59 | 487 | |
c47206e2 RPM |
488 | max_grefs = req->nr_phys_segments; |
489 | if (max_grefs > BLKIF_MAX_SEGMENTS_PER_REQUEST) | |
490 | /* | |
491 | * If we are using indirect segments we need to account | |
492 | * for the indirect grefs used in the request. | |
493 | */ | |
494 | max_grefs += INDIRECT_GREFS(req->nr_phys_segments); | |
402b27f9 RPM |
495 | |
496 | /* Check if we have enough grants to allocate a requests */ | |
497 | if (info->persistent_gnts_c < max_grefs) { | |
0a8704a5 RPM |
498 | new_persistent_gnts = 1; |
499 | if (gnttab_alloc_grant_references( | |
402b27f9 | 500 | max_grefs - info->persistent_gnts_c, |
0a8704a5 RPM |
501 | &gref_head) < 0) { |
502 | gnttab_request_free_callback( | |
503 | &info->callback, | |
504 | blkif_restart_queue_callback, | |
505 | info, | |
402b27f9 | 506 | max_grefs); |
0a8704a5 RPM |
507 | return 1; |
508 | } | |
509 | } else | |
510 | new_persistent_gnts = 0; | |
9f27ee59 JF |
511 | |
512 | /* Fill out a communications ring structure. */ | |
513 | ring_req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt); | |
514 | id = get_id_from_freelist(info); | |
a945b980 | 515 | info->shadow[id].request = req; |
9f27ee59 | 516 | |
33204663 JG |
517 | BUG_ON(info->max_indirect_segments == 0 && |
518 | req->nr_phys_segments > BLKIF_MAX_SEGMENTS_PER_REQUEST); | |
519 | BUG_ON(info->max_indirect_segments && | |
520 | req->nr_phys_segments > info->max_indirect_segments); | |
521 | nseg = blk_rq_map_sg(req->q, req, info->shadow[id].sg); | |
522 | ring_req->u.rw.id = id; | |
523 | if (nseg > BLKIF_MAX_SEGMENTS_PER_REQUEST) { | |
524 | /* | |
525 | * The indirect operation can only be a BLKIF_OP_READ or | |
526 | * BLKIF_OP_WRITE | |
527 | */ | |
528 | BUG_ON(req->cmd_flags & (REQ_FLUSH | REQ_FUA)); | |
529 | ring_req->operation = BLKIF_OP_INDIRECT; | |
530 | ring_req->u.indirect.indirect_op = rq_data_dir(req) ? | |
531 | BLKIF_OP_WRITE : BLKIF_OP_READ; | |
532 | ring_req->u.indirect.sector_number = (blkif_sector_t)blk_rq_pos(req); | |
533 | ring_req->u.indirect.handle = info->handle; | |
534 | ring_req->u.indirect.nr_segments = nseg; | |
ed30bf31 | 535 | } else { |
33204663 JG |
536 | ring_req->u.rw.sector_number = (blkif_sector_t)blk_rq_pos(req); |
537 | ring_req->u.rw.handle = info->handle; | |
538 | ring_req->operation = rq_data_dir(req) ? | |
539 | BLKIF_OP_WRITE : BLKIF_OP_READ; | |
540 | if (req->cmd_flags & (REQ_FLUSH | REQ_FUA)) { | |
402b27f9 | 541 | /* |
33204663 JG |
542 | * Ideally we can do an unordered flush-to-disk. |
543 | * In case the backend onlysupports barriers, use that. | |
544 | * A barrier request a superset of FUA, so we can | |
545 | * implement it the same way. (It's also a FLUSH+FUA, | |
546 | * since it is guaranteed ordered WRT previous writes.) | |
402b27f9 | 547 | */ |
33204663 JG |
548 | switch (info->feature_flush & |
549 | ((REQ_FLUSH|REQ_FUA))) { | |
550 | case REQ_FLUSH|REQ_FUA: | |
551 | ring_req->operation = | |
552 | BLKIF_OP_WRITE_BARRIER; | |
553 | break; | |
554 | case REQ_FLUSH: | |
555 | ring_req->operation = | |
556 | BLKIF_OP_FLUSH_DISKCACHE; | |
557 | break; | |
558 | default: | |
559 | ring_req->operation = 0; | |
560 | } | |
561 | } | |
562 | ring_req->u.rw.nr_segments = nseg; | |
563 | } | |
564 | for_each_sg(info->shadow[id].sg, sg, nseg, i) { | |
565 | fsect = sg->offset >> 9; | |
566 | lsect = fsect + (sg->length >> 9) - 1; | |
567 | ||
568 | if ((ring_req->operation == BLKIF_OP_INDIRECT) && | |
569 | (i % SEGS_PER_INDIRECT_FRAME == 0)) { | |
33204663 JG |
570 | if (segments) |
571 | kunmap_atomic(segments); | |
572 | ||
573 | n = i / SEGS_PER_INDIRECT_FRAME; | |
4f503fbd | 574 | gnt_list_entry = get_indirect_grant(&gref_head, info); |
33204663 | 575 | info->shadow[id].indirect_grants[n] = gnt_list_entry; |
a7a6df22 | 576 | segments = kmap_atomic(gnt_list_entry->page); |
33204663 | 577 | ring_req->u.indirect.indirect_grefs[n] = gnt_list_entry->gref; |
402b27f9 | 578 | } |
402b27f9 | 579 | |
4f503fbd JG |
580 | gnt_list_entry = get_grant(&gref_head, |
581 | xen_page_to_gfn(sg_page(sg)), | |
582 | info); | |
33204663 | 583 | ref = gnt_list_entry->gref; |
0a8704a5 | 584 | |
33204663 | 585 | info->shadow[id].grants_used[i] = gnt_list_entry; |
0a8704a5 | 586 | |
33204663 JG |
587 | if (rq_data_dir(req) && info->feature_persistent) { |
588 | char *bvec_data; | |
589 | void *shared_data; | |
0a8704a5 | 590 | |
33204663 | 591 | BUG_ON(sg->offset + sg->length > PAGE_SIZE); |
0a8704a5 | 592 | |
a7a6df22 | 593 | shared_data = kmap_atomic(gnt_list_entry->page); |
33204663 | 594 | bvec_data = kmap_atomic(sg_page(sg)); |
0a8704a5 | 595 | |
33204663 JG |
596 | /* |
597 | * this does not wipe data stored outside the | |
598 | * range sg->offset..sg->offset+sg->length. | |
599 | * Therefore, blkback *could* see data from | |
600 | * previous requests. This is OK as long as | |
601 | * persistent grants are shared with just one | |
602 | * domain. It may need refactoring if this | |
603 | * changes | |
604 | */ | |
605 | memcpy(shared_data + sg->offset, | |
606 | bvec_data + sg->offset, | |
607 | sg->length); | |
0a8704a5 | 608 | |
33204663 JG |
609 | kunmap_atomic(bvec_data); |
610 | kunmap_atomic(shared_data); | |
611 | } | |
612 | if (ring_req->operation != BLKIF_OP_INDIRECT) { | |
613 | ring_req->u.rw.seg[i] = | |
80bfa2f6 | 614 | (struct blkif_request_segment) { |
33204663 JG |
615 | .gref = ref, |
616 | .first_sect = fsect, | |
617 | .last_sect = lsect }; | |
618 | } else { | |
619 | n = i % SEGS_PER_INDIRECT_FRAME; | |
620 | segments[n] = | |
621 | (struct blkif_request_segment) { | |
622 | .gref = ref, | |
623 | .first_sect = fsect, | |
624 | .last_sect = lsect }; | |
ed30bf31 | 625 | } |
9f27ee59 | 626 | } |
33204663 JG |
627 | if (segments) |
628 | kunmap_atomic(segments); | |
9f27ee59 JF |
629 | |
630 | info->ring.req_prod_pvt++; | |
631 | ||
632 | /* Keep a private copy so we can reissue requests when recovering. */ | |
633 | info->shadow[id].req = *ring_req; | |
634 | ||
0a8704a5 RPM |
635 | if (new_persistent_gnts) |
636 | gnttab_free_grant_references(gref_head); | |
9f27ee59 JF |
637 | |
638 | return 0; | |
639 | } | |
640 | ||
33204663 JG |
641 | /* |
642 | * Generate a Xen blkfront IO request from a blk layer request. Reads | |
643 | * and writes are handled as expected. | |
644 | * | |
645 | * @req: a request struct | |
646 | */ | |
647 | static int blkif_queue_request(struct request *req) | |
648 | { | |
649 | struct blkfront_info *info = req->rq_disk->private_data; | |
650 | ||
651 | if (unlikely(info->connected != BLKIF_STATE_CONNECTED)) | |
652 | return 1; | |
653 | ||
654 | if (unlikely(req->cmd_flags & (REQ_DISCARD | REQ_SECURE))) | |
655 | return blkif_queue_discard_req(req); | |
656 | else | |
657 | return blkif_queue_rw_req(req); | |
658 | } | |
9f27ee59 JF |
659 | |
660 | static inline void flush_requests(struct blkfront_info *info) | |
661 | { | |
662 | int notify; | |
663 | ||
664 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&info->ring, notify); | |
665 | ||
666 | if (notify) | |
667 | notify_remote_via_irq(info->irq); | |
668 | } | |
669 | ||
ad42d391 VK |
670 | static inline bool blkif_request_flush_invalid(struct request *req, |
671 | struct blkfront_info *info) | |
0f1ca65e AA |
672 | { |
673 | return ((req->cmd_type != REQ_TYPE_FS) || | |
ad42d391 VK |
674 | ((req->cmd_flags & REQ_FLUSH) && |
675 | !(info->feature_flush & REQ_FLUSH)) || | |
676 | ((req->cmd_flags & REQ_FUA) && | |
677 | !(info->feature_flush & REQ_FUA))); | |
0f1ca65e AA |
678 | } |
679 | ||
907c3eb1 BL |
680 | static int blkif_queue_rq(struct blk_mq_hw_ctx *hctx, |
681 | const struct blk_mq_queue_data *qd) | |
9f27ee59 | 682 | { |
907c3eb1 | 683 | struct blkfront_info *info = qd->rq->rq_disk->private_data; |
9f27ee59 | 684 | |
907c3eb1 BL |
685 | blk_mq_start_request(qd->rq); |
686 | spin_lock_irq(&info->io_lock); | |
687 | if (RING_FULL(&info->ring)) | |
688 | goto out_busy; | |
9f27ee59 | 689 | |
907c3eb1 BL |
690 | if (blkif_request_flush_invalid(qd->rq, info)) |
691 | goto out_err; | |
296b2f6a | 692 | |
907c3eb1 BL |
693 | if (blkif_queue_request(qd->rq)) |
694 | goto out_busy; | |
296b2f6a | 695 | |
907c3eb1 BL |
696 | flush_requests(info); |
697 | spin_unlock_irq(&info->io_lock); | |
698 | return BLK_MQ_RQ_QUEUE_OK; | |
9f27ee59 | 699 | |
907c3eb1 BL |
700 | out_err: |
701 | spin_unlock_irq(&info->io_lock); | |
702 | return BLK_MQ_RQ_QUEUE_ERROR; | |
9f27ee59 | 703 | |
907c3eb1 BL |
704 | out_busy: |
705 | spin_unlock_irq(&info->io_lock); | |
706 | blk_mq_stop_hw_queue(hctx); | |
707 | return BLK_MQ_RQ_QUEUE_BUSY; | |
9f27ee59 JF |
708 | } |
709 | ||
907c3eb1 BL |
710 | static struct blk_mq_ops blkfront_mq_ops = { |
711 | .queue_rq = blkif_queue_rq, | |
712 | .map_queue = blk_mq_map_queue, | |
713 | }; | |
714 | ||
402b27f9 | 715 | static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size, |
7c4d7d71 | 716 | unsigned int physical_sector_size, |
402b27f9 | 717 | unsigned int segments) |
9f27ee59 | 718 | { |
165125e1 | 719 | struct request_queue *rq; |
ed30bf31 | 720 | struct blkfront_info *info = gd->private_data; |
9f27ee59 | 721 | |
907c3eb1 BL |
722 | memset(&info->tag_set, 0, sizeof(info->tag_set)); |
723 | info->tag_set.ops = &blkfront_mq_ops; | |
724 | info->tag_set.nr_hw_queues = 1; | |
725 | info->tag_set.queue_depth = BLK_RING_SIZE(info); | |
726 | info->tag_set.numa_node = NUMA_NO_NODE; | |
727 | info->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE; | |
728 | info->tag_set.cmd_size = 0; | |
729 | info->tag_set.driver_data = info; | |
730 | ||
731 | if (blk_mq_alloc_tag_set(&info->tag_set)) | |
9f27ee59 | 732 | return -1; |
907c3eb1 BL |
733 | rq = blk_mq_init_queue(&info->tag_set); |
734 | if (IS_ERR(rq)) { | |
735 | blk_mq_free_tag_set(&info->tag_set); | |
736 | return -1; | |
737 | } | |
9f27ee59 | 738 | |
66d352e1 | 739 | queue_flag_set_unlocked(QUEUE_FLAG_VIRT, rq); |
9f27ee59 | 740 | |
ed30bf31 LD |
741 | if (info->feature_discard) { |
742 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, rq); | |
743 | blk_queue_max_discard_sectors(rq, get_capacity(gd)); | |
744 | rq->limits.discard_granularity = info->discard_granularity; | |
745 | rq->limits.discard_alignment = info->discard_alignment; | |
5ea42986 KRW |
746 | if (info->feature_secdiscard) |
747 | queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD, rq); | |
ed30bf31 LD |
748 | } |
749 | ||
9f27ee59 | 750 | /* Hard sector size and max sectors impersonate the equiv. hardware. */ |
e1defc4f | 751 | blk_queue_logical_block_size(rq, sector_size); |
7c4d7d71 | 752 | blk_queue_physical_block_size(rq, physical_sector_size); |
294caaf2 | 753 | blk_queue_max_hw_sectors(rq, (segments * PAGE_SIZE) / 512); |
9f27ee59 JF |
754 | |
755 | /* Each segment in a request is up to an aligned page in size. */ | |
756 | blk_queue_segment_boundary(rq, PAGE_SIZE - 1); | |
757 | blk_queue_max_segment_size(rq, PAGE_SIZE); | |
758 | ||
759 | /* Ensure a merged request will fit in a single I/O ring slot. */ | |
402b27f9 | 760 | blk_queue_max_segments(rq, segments); |
9f27ee59 JF |
761 | |
762 | /* Make sure buffer addresses are sector-aligned. */ | |
763 | blk_queue_dma_alignment(rq, 511); | |
764 | ||
1c91fe1a IC |
765 | /* Make sure we don't use bounce buffers. */ |
766 | blk_queue_bounce_limit(rq, BLK_BOUNCE_ANY); | |
767 | ||
9f27ee59 JF |
768 | gd->queue = rq; |
769 | ||
770 | return 0; | |
771 | } | |
772 | ||
fdf9b965 VK |
773 | static const char *flush_info(unsigned int feature_flush) |
774 | { | |
775 | switch (feature_flush & ((REQ_FLUSH | REQ_FUA))) { | |
776 | case REQ_FLUSH|REQ_FUA: | |
777 | return "barrier: enabled;"; | |
778 | case REQ_FLUSH: | |
779 | return "flush diskcache: enabled;"; | |
780 | default: | |
781 | return "barrier or flush: disabled;"; | |
782 | } | |
783 | } | |
9f27ee59 | 784 | |
4913efe4 | 785 | static void xlvbd_flush(struct blkfront_info *info) |
9f27ee59 | 786 | { |
4913efe4 | 787 | blk_queue_flush(info->rq, info->feature_flush); |
fdf9b965 VK |
788 | pr_info("blkfront: %s: %s %s %s %s %s\n", |
789 | info->gd->disk_name, flush_info(info->feature_flush), | |
790 | "persistent grants:", info->feature_persistent ? | |
791 | "enabled;" : "disabled;", "indirect descriptors:", | |
792 | info->max_indirect_segments ? "enabled;" : "disabled;"); | |
9f27ee59 JF |
793 | } |
794 | ||
c80a4209 SS |
795 | static int xen_translate_vdev(int vdevice, int *minor, unsigned int *offset) |
796 | { | |
797 | int major; | |
798 | major = BLKIF_MAJOR(vdevice); | |
799 | *minor = BLKIF_MINOR(vdevice); | |
800 | switch (major) { | |
801 | case XEN_IDE0_MAJOR: | |
802 | *offset = (*minor / 64) + EMULATED_HD_DISK_NAME_OFFSET; | |
803 | *minor = ((*minor / 64) * PARTS_PER_DISK) + | |
804 | EMULATED_HD_DISK_MINOR_OFFSET; | |
805 | break; | |
806 | case XEN_IDE1_MAJOR: | |
807 | *offset = (*minor / 64) + 2 + EMULATED_HD_DISK_NAME_OFFSET; | |
808 | *minor = (((*minor / 64) + 2) * PARTS_PER_DISK) + | |
809 | EMULATED_HD_DISK_MINOR_OFFSET; | |
810 | break; | |
811 | case XEN_SCSI_DISK0_MAJOR: | |
812 | *offset = (*minor / PARTS_PER_DISK) + EMULATED_SD_DISK_NAME_OFFSET; | |
813 | *minor = *minor + EMULATED_SD_DISK_MINOR_OFFSET; | |
814 | break; | |
815 | case XEN_SCSI_DISK1_MAJOR: | |
816 | case XEN_SCSI_DISK2_MAJOR: | |
817 | case XEN_SCSI_DISK3_MAJOR: | |
818 | case XEN_SCSI_DISK4_MAJOR: | |
819 | case XEN_SCSI_DISK5_MAJOR: | |
820 | case XEN_SCSI_DISK6_MAJOR: | |
821 | case XEN_SCSI_DISK7_MAJOR: | |
822 | *offset = (*minor / PARTS_PER_DISK) + | |
823 | ((major - XEN_SCSI_DISK1_MAJOR + 1) * 16) + | |
824 | EMULATED_SD_DISK_NAME_OFFSET; | |
825 | *minor = *minor + | |
826 | ((major - XEN_SCSI_DISK1_MAJOR + 1) * 16 * PARTS_PER_DISK) + | |
827 | EMULATED_SD_DISK_MINOR_OFFSET; | |
828 | break; | |
829 | case XEN_SCSI_DISK8_MAJOR: | |
830 | case XEN_SCSI_DISK9_MAJOR: | |
831 | case XEN_SCSI_DISK10_MAJOR: | |
832 | case XEN_SCSI_DISK11_MAJOR: | |
833 | case XEN_SCSI_DISK12_MAJOR: | |
834 | case XEN_SCSI_DISK13_MAJOR: | |
835 | case XEN_SCSI_DISK14_MAJOR: | |
836 | case XEN_SCSI_DISK15_MAJOR: | |
837 | *offset = (*minor / PARTS_PER_DISK) + | |
838 | ((major - XEN_SCSI_DISK8_MAJOR + 8) * 16) + | |
839 | EMULATED_SD_DISK_NAME_OFFSET; | |
840 | *minor = *minor + | |
841 | ((major - XEN_SCSI_DISK8_MAJOR + 8) * 16 * PARTS_PER_DISK) + | |
842 | EMULATED_SD_DISK_MINOR_OFFSET; | |
843 | break; | |
844 | case XENVBD_MAJOR: | |
845 | *offset = *minor / PARTS_PER_DISK; | |
846 | break; | |
847 | default: | |
848 | printk(KERN_WARNING "blkfront: your disk configuration is " | |
849 | "incorrect, please use an xvd device instead\n"); | |
850 | return -ENODEV; | |
851 | } | |
852 | return 0; | |
853 | } | |
9f27ee59 | 854 | |
e77c78c0 JB |
855 | static char *encode_disk_name(char *ptr, unsigned int n) |
856 | { | |
857 | if (n >= 26) | |
858 | ptr = encode_disk_name(ptr, n / 26 - 1); | |
859 | *ptr = 'a' + n % 26; | |
860 | return ptr + 1; | |
861 | } | |
862 | ||
9246b5f0 CL |
863 | static int xlvbd_alloc_gendisk(blkif_sector_t capacity, |
864 | struct blkfront_info *info, | |
7c4d7d71 SB |
865 | u16 vdisk_info, u16 sector_size, |
866 | unsigned int physical_sector_size) | |
9f27ee59 JF |
867 | { |
868 | struct gendisk *gd; | |
869 | int nr_minors = 1; | |
c80a4209 | 870 | int err; |
9246b5f0 CL |
871 | unsigned int offset; |
872 | int minor; | |
873 | int nr_parts; | |
e77c78c0 | 874 | char *ptr; |
9f27ee59 JF |
875 | |
876 | BUG_ON(info->gd != NULL); | |
877 | BUG_ON(info->rq != NULL); | |
878 | ||
9246b5f0 CL |
879 | if ((info->vdevice>>EXT_SHIFT) > 1) { |
880 | /* this is above the extended range; something is wrong */ | |
881 | printk(KERN_WARNING "blkfront: vdevice 0x%x is above the extended range; ignoring\n", info->vdevice); | |
882 | return -ENODEV; | |
883 | } | |
884 | ||
885 | if (!VDEV_IS_EXTENDED(info->vdevice)) { | |
c80a4209 SS |
886 | err = xen_translate_vdev(info->vdevice, &minor, &offset); |
887 | if (err) | |
888 | return err; | |
889 | nr_parts = PARTS_PER_DISK; | |
9246b5f0 CL |
890 | } else { |
891 | minor = BLKIF_MINOR_EXT(info->vdevice); | |
892 | nr_parts = PARTS_PER_EXT_DISK; | |
c80a4209 | 893 | offset = minor / nr_parts; |
89153b5c | 894 | if (xen_hvm_domain() && offset < EMULATED_HD_DISK_NAME_OFFSET + 4) |
c80a4209 SS |
895 | printk(KERN_WARNING "blkfront: vdevice 0x%x might conflict with " |
896 | "emulated IDE disks,\n\t choose an xvd device name" | |
897 | "from xvde on\n", info->vdevice); | |
9246b5f0 | 898 | } |
e77c78c0 JB |
899 | if (minor >> MINORBITS) { |
900 | pr_warn("blkfront: %#x's minor (%#x) out of range; ignoring\n", | |
901 | info->vdevice, minor); | |
902 | return -ENODEV; | |
903 | } | |
9246b5f0 CL |
904 | |
905 | if ((minor % nr_parts) == 0) | |
906 | nr_minors = nr_parts; | |
9f27ee59 | 907 | |
0e345826 JB |
908 | err = xlbd_reserve_minors(minor, nr_minors); |
909 | if (err) | |
910 | goto out; | |
911 | err = -ENODEV; | |
912 | ||
9f27ee59 JF |
913 | gd = alloc_disk(nr_minors); |
914 | if (gd == NULL) | |
0e345826 | 915 | goto release; |
9f27ee59 | 916 | |
e77c78c0 JB |
917 | strcpy(gd->disk_name, DEV_NAME); |
918 | ptr = encode_disk_name(gd->disk_name + sizeof(DEV_NAME) - 1, offset); | |
919 | BUG_ON(ptr >= gd->disk_name + DISK_NAME_LEN); | |
920 | if (nr_minors > 1) | |
921 | *ptr = 0; | |
922 | else | |
923 | snprintf(ptr, gd->disk_name + DISK_NAME_LEN - ptr, | |
924 | "%d", minor & (nr_parts - 1)); | |
9f27ee59 JF |
925 | |
926 | gd->major = XENVBD_MAJOR; | |
927 | gd->first_minor = minor; | |
928 | gd->fops = &xlvbd_block_fops; | |
929 | gd->private_data = info; | |
930 | gd->driverfs_dev = &(info->xbdev->dev); | |
931 | set_capacity(gd, capacity); | |
932 | ||
7c4d7d71 | 933 | if (xlvbd_init_blk_queue(gd, sector_size, physical_sector_size, |
402b27f9 RPM |
934 | info->max_indirect_segments ? : |
935 | BLKIF_MAX_SEGMENTS_PER_REQUEST)) { | |
9f27ee59 | 936 | del_gendisk(gd); |
0e345826 | 937 | goto release; |
9f27ee59 JF |
938 | } |
939 | ||
940 | info->rq = gd->queue; | |
941 | info->gd = gd; | |
942 | ||
4913efe4 | 943 | xlvbd_flush(info); |
9f27ee59 JF |
944 | |
945 | if (vdisk_info & VDISK_READONLY) | |
946 | set_disk_ro(gd, 1); | |
947 | ||
948 | if (vdisk_info & VDISK_REMOVABLE) | |
949 | gd->flags |= GENHD_FL_REMOVABLE; | |
950 | ||
951 | if (vdisk_info & VDISK_CDROM) | |
952 | gd->flags |= GENHD_FL_CD; | |
953 | ||
954 | return 0; | |
955 | ||
0e345826 JB |
956 | release: |
957 | xlbd_release_minors(minor, nr_minors); | |
9f27ee59 JF |
958 | out: |
959 | return err; | |
960 | } | |
961 | ||
a66b5aeb DS |
962 | static void xlvbd_release_gendisk(struct blkfront_info *info) |
963 | { | |
964 | unsigned int minor, nr_minors; | |
a66b5aeb DS |
965 | |
966 | if (info->rq == NULL) | |
967 | return; | |
968 | ||
a66b5aeb | 969 | /* No more blkif_request(). */ |
907c3eb1 | 970 | blk_mq_stop_hw_queues(info->rq); |
a66b5aeb DS |
971 | |
972 | /* No more gnttab callback work. */ | |
973 | gnttab_cancel_free_callback(&info->callback); | |
a66b5aeb DS |
974 | |
975 | /* Flush gnttab callback work. Must be done with no locks held. */ | |
43829731 | 976 | flush_work(&info->work); |
a66b5aeb DS |
977 | |
978 | del_gendisk(info->gd); | |
979 | ||
980 | minor = info->gd->first_minor; | |
981 | nr_minors = info->gd->minors; | |
982 | xlbd_release_minors(minor, nr_minors); | |
983 | ||
984 | blk_cleanup_queue(info->rq); | |
907c3eb1 | 985 | blk_mq_free_tag_set(&info->tag_set); |
a66b5aeb DS |
986 | info->rq = NULL; |
987 | ||
988 | put_disk(info->gd); | |
989 | info->gd = NULL; | |
990 | } | |
991 | ||
907c3eb1 | 992 | /* Must be called with io_lock holded */ |
9f27ee59 JF |
993 | static void kick_pending_request_queues(struct blkfront_info *info) |
994 | { | |
907c3eb1 BL |
995 | if (!RING_FULL(&info->ring)) |
996 | blk_mq_start_stopped_hw_queues(info->rq, true); | |
9f27ee59 JF |
997 | } |
998 | ||
999 | static void blkif_restart_queue(struct work_struct *work) | |
1000 | { | |
1001 | struct blkfront_info *info = container_of(work, struct blkfront_info, work); | |
1002 | ||
3467811e | 1003 | spin_lock_irq(&info->io_lock); |
9f27ee59 JF |
1004 | if (info->connected == BLKIF_STATE_CONNECTED) |
1005 | kick_pending_request_queues(info); | |
3467811e | 1006 | spin_unlock_irq(&info->io_lock); |
9f27ee59 JF |
1007 | } |
1008 | ||
1009 | static void blkif_free(struct blkfront_info *info, int suspend) | |
1010 | { | |
155b7edb RPM |
1011 | struct grant *persistent_gnt; |
1012 | struct grant *n; | |
402b27f9 | 1013 | int i, j, segs; |
0a8704a5 | 1014 | |
9f27ee59 | 1015 | /* Prevent new requests being issued until we fix things up. */ |
3467811e | 1016 | spin_lock_irq(&info->io_lock); |
9f27ee59 JF |
1017 | info->connected = suspend ? |
1018 | BLKIF_STATE_SUSPENDED : BLKIF_STATE_DISCONNECTED; | |
1019 | /* No more blkif_request(). */ | |
1020 | if (info->rq) | |
907c3eb1 | 1021 | blk_mq_stop_hw_queues(info->rq); |
0a8704a5 RPM |
1022 | |
1023 | /* Remove all persistent grants */ | |
bfe11d6d | 1024 | if (!list_empty(&info->grants)) { |
155b7edb | 1025 | list_for_each_entry_safe(persistent_gnt, n, |
bfe11d6d | 1026 | &info->grants, node) { |
155b7edb | 1027 | list_del(&persistent_gnt->node); |
9c1e050c RPM |
1028 | if (persistent_gnt->gref != GRANT_INVALID_REF) { |
1029 | gnttab_end_foreign_access(persistent_gnt->gref, | |
1030 | 0, 0UL); | |
1031 | info->persistent_gnts_c--; | |
1032 | } | |
bfe11d6d | 1033 | if (info->feature_persistent) |
a7a6df22 | 1034 | __free_page(persistent_gnt->page); |
155b7edb | 1035 | kfree(persistent_gnt); |
0a8704a5 | 1036 | } |
0a8704a5 | 1037 | } |
9c1e050c | 1038 | BUG_ON(info->persistent_gnts_c != 0); |
0a8704a5 | 1039 | |
bfe11d6d RPM |
1040 | /* |
1041 | * Remove indirect pages, this only happens when using indirect | |
1042 | * descriptors but not persistent grants | |
1043 | */ | |
1044 | if (!list_empty(&info->indirect_pages)) { | |
1045 | struct page *indirect_page, *n; | |
1046 | ||
1047 | BUG_ON(info->feature_persistent); | |
1048 | list_for_each_entry_safe(indirect_page, n, &info->indirect_pages, lru) { | |
1049 | list_del(&indirect_page->lru); | |
1050 | __free_page(indirect_page); | |
1051 | } | |
1052 | } | |
1053 | ||
86839c56 | 1054 | for (i = 0; i < BLK_RING_SIZE(info); i++) { |
402b27f9 RPM |
1055 | /* |
1056 | * Clear persistent grants present in requests already | |
1057 | * on the shared ring | |
1058 | */ | |
1059 | if (!info->shadow[i].request) | |
1060 | goto free_shadow; | |
1061 | ||
1062 | segs = info->shadow[i].req.operation == BLKIF_OP_INDIRECT ? | |
1063 | info->shadow[i].req.u.indirect.nr_segments : | |
1064 | info->shadow[i].req.u.rw.nr_segments; | |
1065 | for (j = 0; j < segs; j++) { | |
1066 | persistent_gnt = info->shadow[i].grants_used[j]; | |
1067 | gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL); | |
bfe11d6d | 1068 | if (info->feature_persistent) |
a7a6df22 | 1069 | __free_page(persistent_gnt->page); |
402b27f9 RPM |
1070 | kfree(persistent_gnt); |
1071 | } | |
1072 | ||
1073 | if (info->shadow[i].req.operation != BLKIF_OP_INDIRECT) | |
1074 | /* | |
1075 | * If this is not an indirect operation don't try to | |
1076 | * free indirect segments | |
1077 | */ | |
1078 | goto free_shadow; | |
1079 | ||
1080 | for (j = 0; j < INDIRECT_GREFS(segs); j++) { | |
1081 | persistent_gnt = info->shadow[i].indirect_grants[j]; | |
1082 | gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL); | |
a7a6df22 | 1083 | __free_page(persistent_gnt->page); |
402b27f9 RPM |
1084 | kfree(persistent_gnt); |
1085 | } | |
1086 | ||
1087 | free_shadow: | |
1088 | kfree(info->shadow[i].grants_used); | |
1089 | info->shadow[i].grants_used = NULL; | |
1090 | kfree(info->shadow[i].indirect_grants); | |
1091 | info->shadow[i].indirect_grants = NULL; | |
b7649158 RPM |
1092 | kfree(info->shadow[i].sg); |
1093 | info->shadow[i].sg = NULL; | |
402b27f9 RPM |
1094 | } |
1095 | ||
9f27ee59 JF |
1096 | /* No more gnttab callback work. */ |
1097 | gnttab_cancel_free_callback(&info->callback); | |
3467811e | 1098 | spin_unlock_irq(&info->io_lock); |
9f27ee59 JF |
1099 | |
1100 | /* Flush gnttab callback work. Must be done with no locks held. */ | |
43829731 | 1101 | flush_work(&info->work); |
9f27ee59 JF |
1102 | |
1103 | /* Free resources associated with old device channel. */ | |
86839c56 BL |
1104 | for (i = 0; i < info->nr_ring_pages; i++) { |
1105 | if (info->ring_ref[i] != GRANT_INVALID_REF) { | |
1106 | gnttab_end_foreign_access(info->ring_ref[i], 0, 0); | |
1107 | info->ring_ref[i] = GRANT_INVALID_REF; | |
1108 | } | |
9f27ee59 | 1109 | } |
86839c56 BL |
1110 | free_pages((unsigned long)info->ring.sring, get_order(info->nr_ring_pages * PAGE_SIZE)); |
1111 | info->ring.sring = NULL; | |
1112 | ||
9f27ee59 JF |
1113 | if (info->irq) |
1114 | unbind_from_irqhandler(info->irq, info); | |
1115 | info->evtchn = info->irq = 0; | |
1116 | ||
1117 | } | |
1118 | ||
0a8704a5 RPM |
1119 | static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info, |
1120 | struct blkif_response *bret) | |
9f27ee59 | 1121 | { |
d62f6918 | 1122 | int i = 0; |
b7649158 | 1123 | struct scatterlist *sg; |
0a8704a5 RPM |
1124 | char *bvec_data; |
1125 | void *shared_data; | |
402b27f9 RPM |
1126 | int nseg; |
1127 | ||
1128 | nseg = s->req.operation == BLKIF_OP_INDIRECT ? | |
1129 | s->req.u.indirect.nr_segments : s->req.u.rw.nr_segments; | |
0a8704a5 | 1130 | |
bfe11d6d | 1131 | if (bret->operation == BLKIF_OP_READ && info->feature_persistent) { |
b7649158 RPM |
1132 | for_each_sg(s->sg, sg, nseg, i) { |
1133 | BUG_ON(sg->offset + sg->length > PAGE_SIZE); | |
a7a6df22 | 1134 | shared_data = kmap_atomic(s->grants_used[i]->page); |
b7649158 RPM |
1135 | bvec_data = kmap_atomic(sg_page(sg)); |
1136 | memcpy(bvec_data + sg->offset, | |
1137 | shared_data + sg->offset, | |
1138 | sg->length); | |
1139 | kunmap_atomic(bvec_data); | |
0a8704a5 | 1140 | kunmap_atomic(shared_data); |
0a8704a5 RPM |
1141 | } |
1142 | } | |
1143 | /* Add the persistent grant into the list of free grants */ | |
402b27f9 | 1144 | for (i = 0; i < nseg; i++) { |
fbe363c4 RPM |
1145 | if (gnttab_query_foreign_access(s->grants_used[i]->gref)) { |
1146 | /* | |
1147 | * If the grant is still mapped by the backend (the | |
1148 | * backend has chosen to make this grant persistent) | |
1149 | * we add it at the head of the list, so it will be | |
1150 | * reused first. | |
1151 | */ | |
bfe11d6d RPM |
1152 | if (!info->feature_persistent) |
1153 | pr_alert_ratelimited("backed has not unmapped grant: %u\n", | |
1154 | s->grants_used[i]->gref); | |
1155 | list_add(&s->grants_used[i]->node, &info->grants); | |
fbe363c4 RPM |
1156 | info->persistent_gnts_c++; |
1157 | } else { | |
1158 | /* | |
1159 | * If the grant is not mapped by the backend we end the | |
1160 | * foreign access and add it to the tail of the list, | |
1161 | * so it will not be picked again unless we run out of | |
1162 | * persistent grants. | |
1163 | */ | |
1164 | gnttab_end_foreign_access(s->grants_used[i]->gref, 0, 0UL); | |
1165 | s->grants_used[i]->gref = GRANT_INVALID_REF; | |
bfe11d6d | 1166 | list_add_tail(&s->grants_used[i]->node, &info->grants); |
fbe363c4 | 1167 | } |
0a8704a5 | 1168 | } |
402b27f9 RPM |
1169 | if (s->req.operation == BLKIF_OP_INDIRECT) { |
1170 | for (i = 0; i < INDIRECT_GREFS(nseg); i++) { | |
fbe363c4 | 1171 | if (gnttab_query_foreign_access(s->indirect_grants[i]->gref)) { |
bfe11d6d RPM |
1172 | if (!info->feature_persistent) |
1173 | pr_alert_ratelimited("backed has not unmapped grant: %u\n", | |
1174 | s->indirect_grants[i]->gref); | |
1175 | list_add(&s->indirect_grants[i]->node, &info->grants); | |
fbe363c4 RPM |
1176 | info->persistent_gnts_c++; |
1177 | } else { | |
bfe11d6d RPM |
1178 | struct page *indirect_page; |
1179 | ||
fbe363c4 | 1180 | gnttab_end_foreign_access(s->indirect_grants[i]->gref, 0, 0UL); |
bfe11d6d RPM |
1181 | /* |
1182 | * Add the used indirect page back to the list of | |
1183 | * available pages for indirect grefs. | |
1184 | */ | |
7b076750 | 1185 | if (!info->feature_persistent) { |
a7a6df22 | 1186 | indirect_page = s->indirect_grants[i]->page; |
7b076750 BL |
1187 | list_add(&indirect_page->lru, &info->indirect_pages); |
1188 | } | |
fbe363c4 | 1189 | s->indirect_grants[i]->gref = GRANT_INVALID_REF; |
bfe11d6d | 1190 | list_add_tail(&s->indirect_grants[i]->node, &info->grants); |
fbe363c4 | 1191 | } |
402b27f9 RPM |
1192 | } |
1193 | } | |
9f27ee59 JF |
1194 | } |
1195 | ||
1196 | static irqreturn_t blkif_interrupt(int irq, void *dev_id) | |
1197 | { | |
1198 | struct request *req; | |
1199 | struct blkif_response *bret; | |
1200 | RING_IDX i, rp; | |
1201 | unsigned long flags; | |
1202 | struct blkfront_info *info = (struct blkfront_info *)dev_id; | |
f4829a9b | 1203 | int error; |
9f27ee59 | 1204 | |
3467811e | 1205 | spin_lock_irqsave(&info->io_lock, flags); |
9f27ee59 JF |
1206 | |
1207 | if (unlikely(info->connected != BLKIF_STATE_CONNECTED)) { | |
3467811e | 1208 | spin_unlock_irqrestore(&info->io_lock, flags); |
9f27ee59 JF |
1209 | return IRQ_HANDLED; |
1210 | } | |
1211 | ||
1212 | again: | |
1213 | rp = info->ring.sring->rsp_prod; | |
1214 | rmb(); /* Ensure we see queued responses up to 'rp'. */ | |
1215 | ||
1216 | for (i = info->ring.rsp_cons; i != rp; i++) { | |
1217 | unsigned long id; | |
9f27ee59 JF |
1218 | |
1219 | bret = RING_GET_RESPONSE(&info->ring, i); | |
1220 | id = bret->id; | |
6878c32e KRW |
1221 | /* |
1222 | * The backend has messed up and given us an id that we would | |
1223 | * never have given to it (we stamp it up to BLK_RING_SIZE - | |
1224 | * look in get_id_from_freelist. | |
1225 | */ | |
86839c56 | 1226 | if (id >= BLK_RING_SIZE(info)) { |
6878c32e KRW |
1227 | WARN(1, "%s: response to %s has incorrect id (%ld)\n", |
1228 | info->gd->disk_name, op_name(bret->operation), id); | |
1229 | /* We can't safely get the 'struct request' as | |
1230 | * the id is busted. */ | |
1231 | continue; | |
1232 | } | |
a945b980 | 1233 | req = info->shadow[id].request; |
9f27ee59 | 1234 | |
5ea42986 | 1235 | if (bret->operation != BLKIF_OP_DISCARD) |
0a8704a5 | 1236 | blkif_completion(&info->shadow[id], info, bret); |
9f27ee59 | 1237 | |
6878c32e KRW |
1238 | if (add_id_to_freelist(info, id)) { |
1239 | WARN(1, "%s: response to %s (id %ld) couldn't be recycled!\n", | |
1240 | info->gd->disk_name, op_name(bret->operation), id); | |
1241 | continue; | |
1242 | } | |
9f27ee59 | 1243 | |
f4829a9b | 1244 | error = (bret->status == BLKIF_RSP_OKAY) ? 0 : -EIO; |
9f27ee59 | 1245 | switch (bret->operation) { |
ed30bf31 LD |
1246 | case BLKIF_OP_DISCARD: |
1247 | if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) { | |
1248 | struct request_queue *rq = info->rq; | |
6878c32e KRW |
1249 | printk(KERN_WARNING "blkfront: %s: %s op failed\n", |
1250 | info->gd->disk_name, op_name(bret->operation)); | |
f4829a9b | 1251 | error = -EOPNOTSUPP; |
ed30bf31 | 1252 | info->feature_discard = 0; |
5ea42986 | 1253 | info->feature_secdiscard = 0; |
ed30bf31 | 1254 | queue_flag_clear(QUEUE_FLAG_DISCARD, rq); |
5ea42986 | 1255 | queue_flag_clear(QUEUE_FLAG_SECDISCARD, rq); |
ed30bf31 | 1256 | } |
f4829a9b | 1257 | blk_mq_complete_request(req, error); |
ed30bf31 | 1258 | break; |
edf6ef59 | 1259 | case BLKIF_OP_FLUSH_DISKCACHE: |
9f27ee59 JF |
1260 | case BLKIF_OP_WRITE_BARRIER: |
1261 | if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) { | |
6878c32e KRW |
1262 | printk(KERN_WARNING "blkfront: %s: %s op failed\n", |
1263 | info->gd->disk_name, op_name(bret->operation)); | |
f4829a9b | 1264 | error = -EOPNOTSUPP; |
dcb8baec JF |
1265 | } |
1266 | if (unlikely(bret->status == BLKIF_RSP_ERROR && | |
97e36834 | 1267 | info->shadow[id].req.u.rw.nr_segments == 0)) { |
6878c32e KRW |
1268 | printk(KERN_WARNING "blkfront: %s: empty %s op failed\n", |
1269 | info->gd->disk_name, op_name(bret->operation)); | |
f4829a9b | 1270 | error = -EOPNOTSUPP; |
dcb8baec | 1271 | } |
f4829a9b CH |
1272 | if (unlikely(error)) { |
1273 | if (error == -EOPNOTSUPP) | |
1274 | error = 0; | |
4913efe4 TH |
1275 | info->feature_flush = 0; |
1276 | xlvbd_flush(info); | |
9f27ee59 JF |
1277 | } |
1278 | /* fall through */ | |
1279 | case BLKIF_OP_READ: | |
1280 | case BLKIF_OP_WRITE: | |
1281 | if (unlikely(bret->status != BLKIF_RSP_OKAY)) | |
1282 | dev_dbg(&info->xbdev->dev, "Bad return from blkdev data " | |
1283 | "request: %x\n", bret->status); | |
1284 | ||
f4829a9b | 1285 | blk_mq_complete_request(req, error); |
9f27ee59 JF |
1286 | break; |
1287 | default: | |
1288 | BUG(); | |
1289 | } | |
1290 | } | |
1291 | ||
1292 | info->ring.rsp_cons = i; | |
1293 | ||
1294 | if (i != info->ring.req_prod_pvt) { | |
1295 | int more_to_do; | |
1296 | RING_FINAL_CHECK_FOR_RESPONSES(&info->ring, more_to_do); | |
1297 | if (more_to_do) | |
1298 | goto again; | |
1299 | } else | |
1300 | info->ring.sring->rsp_event = i + 1; | |
1301 | ||
1302 | kick_pending_request_queues(info); | |
1303 | ||
3467811e | 1304 | spin_unlock_irqrestore(&info->io_lock, flags); |
9f27ee59 JF |
1305 | |
1306 | return IRQ_HANDLED; | |
1307 | } | |
1308 | ||
1309 | ||
1310 | static int setup_blkring(struct xenbus_device *dev, | |
1311 | struct blkfront_info *info) | |
1312 | { | |
1313 | struct blkif_sring *sring; | |
86839c56 BL |
1314 | int err, i; |
1315 | unsigned long ring_size = info->nr_ring_pages * PAGE_SIZE; | |
1316 | grant_ref_t gref[XENBUS_MAX_RING_PAGES]; | |
9f27ee59 | 1317 | |
86839c56 BL |
1318 | for (i = 0; i < info->nr_ring_pages; i++) |
1319 | info->ring_ref[i] = GRANT_INVALID_REF; | |
9f27ee59 | 1320 | |
86839c56 BL |
1321 | sring = (struct blkif_sring *)__get_free_pages(GFP_NOIO | __GFP_HIGH, |
1322 | get_order(ring_size)); | |
9f27ee59 JF |
1323 | if (!sring) { |
1324 | xenbus_dev_fatal(dev, -ENOMEM, "allocating shared ring"); | |
1325 | return -ENOMEM; | |
1326 | } | |
1327 | SHARED_RING_INIT(sring); | |
86839c56 | 1328 | FRONT_RING_INIT(&info->ring, sring, ring_size); |
9e973e64 | 1329 | |
86839c56 | 1330 | err = xenbus_grant_ring(dev, info->ring.sring, info->nr_ring_pages, gref); |
9f27ee59 | 1331 | if (err < 0) { |
86839c56 | 1332 | free_pages((unsigned long)sring, get_order(ring_size)); |
9f27ee59 JF |
1333 | info->ring.sring = NULL; |
1334 | goto fail; | |
1335 | } | |
86839c56 BL |
1336 | for (i = 0; i < info->nr_ring_pages; i++) |
1337 | info->ring_ref[i] = gref[i]; | |
9f27ee59 JF |
1338 | |
1339 | err = xenbus_alloc_evtchn(dev, &info->evtchn); | |
1340 | if (err) | |
1341 | goto fail; | |
1342 | ||
89c30f16 TT |
1343 | err = bind_evtchn_to_irqhandler(info->evtchn, blkif_interrupt, 0, |
1344 | "blkif", info); | |
9f27ee59 JF |
1345 | if (err <= 0) { |
1346 | xenbus_dev_fatal(dev, err, | |
1347 | "bind_evtchn_to_irqhandler failed"); | |
1348 | goto fail; | |
1349 | } | |
1350 | info->irq = err; | |
1351 | ||
1352 | return 0; | |
1353 | fail: | |
1354 | blkif_free(info, 0); | |
1355 | return err; | |
1356 | } | |
1357 | ||
1358 | ||
1359 | /* Common code used when first setting up, and when resuming. */ | |
203fd61f | 1360 | static int talk_to_blkback(struct xenbus_device *dev, |
9f27ee59 JF |
1361 | struct blkfront_info *info) |
1362 | { | |
1363 | const char *message = NULL; | |
1364 | struct xenbus_transaction xbt; | |
86839c56 BL |
1365 | int err, i; |
1366 | unsigned int max_page_order = 0; | |
1367 | unsigned int ring_page_order = 0; | |
1368 | ||
1369 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, | |
1370 | "max-ring-page-order", "%u", &max_page_order); | |
1371 | if (err != 1) | |
1372 | info->nr_ring_pages = 1; | |
1373 | else { | |
1374 | ring_page_order = min(xen_blkif_max_ring_order, max_page_order); | |
1375 | info->nr_ring_pages = 1 << ring_page_order; | |
1376 | } | |
9f27ee59 JF |
1377 | |
1378 | /* Create shared ring, alloc event channel. */ | |
1379 | err = setup_blkring(dev, info); | |
1380 | if (err) | |
1381 | goto out; | |
1382 | ||
1383 | again: | |
1384 | err = xenbus_transaction_start(&xbt); | |
1385 | if (err) { | |
1386 | xenbus_dev_fatal(dev, err, "starting transaction"); | |
1387 | goto destroy_blkring; | |
1388 | } | |
1389 | ||
86839c56 BL |
1390 | if (info->nr_ring_pages == 1) { |
1391 | err = xenbus_printf(xbt, dev->nodename, | |
1392 | "ring-ref", "%u", info->ring_ref[0]); | |
1393 | if (err) { | |
1394 | message = "writing ring-ref"; | |
1395 | goto abort_transaction; | |
1396 | } | |
1397 | } else { | |
1398 | err = xenbus_printf(xbt, dev->nodename, | |
1399 | "ring-page-order", "%u", ring_page_order); | |
1400 | if (err) { | |
1401 | message = "writing ring-page-order"; | |
1402 | goto abort_transaction; | |
1403 | } | |
1404 | ||
1405 | for (i = 0; i < info->nr_ring_pages; i++) { | |
1406 | char ring_ref_name[RINGREF_NAME_LEN]; | |
1407 | ||
1408 | snprintf(ring_ref_name, RINGREF_NAME_LEN, "ring-ref%u", i); | |
1409 | err = xenbus_printf(xbt, dev->nodename, ring_ref_name, | |
1410 | "%u", info->ring_ref[i]); | |
1411 | if (err) { | |
1412 | message = "writing ring-ref"; | |
1413 | goto abort_transaction; | |
1414 | } | |
1415 | } | |
9f27ee59 JF |
1416 | } |
1417 | err = xenbus_printf(xbt, dev->nodename, | |
1418 | "event-channel", "%u", info->evtchn); | |
1419 | if (err) { | |
1420 | message = "writing event-channel"; | |
1421 | goto abort_transaction; | |
1422 | } | |
3e334239 MA |
1423 | err = xenbus_printf(xbt, dev->nodename, "protocol", "%s", |
1424 | XEN_IO_PROTO_ABI_NATIVE); | |
1425 | if (err) { | |
1426 | message = "writing protocol"; | |
1427 | goto abort_transaction; | |
1428 | } | |
0a8704a5 | 1429 | err = xenbus_printf(xbt, dev->nodename, |
cb5bd4d1 | 1430 | "feature-persistent", "%u", 1); |
0a8704a5 RPM |
1431 | if (err) |
1432 | dev_warn(&dev->dev, | |
1433 | "writing persistent grants feature to xenbus"); | |
9f27ee59 JF |
1434 | |
1435 | err = xenbus_transaction_end(xbt, 0); | |
1436 | if (err) { | |
1437 | if (err == -EAGAIN) | |
1438 | goto again; | |
1439 | xenbus_dev_fatal(dev, err, "completing transaction"); | |
1440 | goto destroy_blkring; | |
1441 | } | |
1442 | ||
86839c56 BL |
1443 | for (i = 0; i < BLK_RING_SIZE(info); i++) |
1444 | info->shadow[i].req.u.rw.id = i+1; | |
1445 | info->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff; | |
9f27ee59 JF |
1446 | xenbus_switch_state(dev, XenbusStateInitialised); |
1447 | ||
1448 | return 0; | |
1449 | ||
1450 | abort_transaction: | |
1451 | xenbus_transaction_end(xbt, 1); | |
1452 | if (message) | |
1453 | xenbus_dev_fatal(dev, err, "%s", message); | |
1454 | destroy_blkring: | |
1455 | blkif_free(info, 0); | |
1456 | out: | |
1457 | return err; | |
1458 | } | |
1459 | ||
9f27ee59 JF |
1460 | /** |
1461 | * Entry point to this code when a new device is created. Allocate the basic | |
1462 | * structures and the ring buffer for communication with the backend, and | |
1463 | * inform the backend of the appropriate details for those. Switch to | |
1464 | * Initialised state. | |
1465 | */ | |
1466 | static int blkfront_probe(struct xenbus_device *dev, | |
1467 | const struct xenbus_device_id *id) | |
1468 | { | |
86839c56 | 1469 | int err, vdevice; |
9f27ee59 JF |
1470 | struct blkfront_info *info; |
1471 | ||
1472 | /* FIXME: Use dynamic device id if this is not set. */ | |
1473 | err = xenbus_scanf(XBT_NIL, dev->nodename, | |
1474 | "virtual-device", "%i", &vdevice); | |
1475 | if (err != 1) { | |
9246b5f0 CL |
1476 | /* go looking in the extended area instead */ |
1477 | err = xenbus_scanf(XBT_NIL, dev->nodename, "virtual-device-ext", | |
1478 | "%i", &vdevice); | |
1479 | if (err != 1) { | |
1480 | xenbus_dev_fatal(dev, err, "reading virtual-device"); | |
1481 | return err; | |
1482 | } | |
9f27ee59 JF |
1483 | } |
1484 | ||
b98a409b SS |
1485 | if (xen_hvm_domain()) { |
1486 | char *type; | |
1487 | int len; | |
1488 | /* no unplug has been done: do not hook devices != xen vbds */ | |
51c71a3b | 1489 | if (xen_has_pv_and_legacy_disk_devices()) { |
b98a409b SS |
1490 | int major; |
1491 | ||
1492 | if (!VDEV_IS_EXTENDED(vdevice)) | |
1493 | major = BLKIF_MAJOR(vdevice); | |
1494 | else | |
1495 | major = XENVBD_MAJOR; | |
1496 | ||
1497 | if (major != XENVBD_MAJOR) { | |
1498 | printk(KERN_INFO | |
1499 | "%s: HVM does not support vbd %d as xen block device\n", | |
02f1f217 | 1500 | __func__, vdevice); |
b98a409b SS |
1501 | return -ENODEV; |
1502 | } | |
1503 | } | |
1504 | /* do not create a PV cdrom device if we are an HVM guest */ | |
1505 | type = xenbus_read(XBT_NIL, dev->nodename, "device-type", &len); | |
1506 | if (IS_ERR(type)) | |
1507 | return -ENODEV; | |
1508 | if (strncmp(type, "cdrom", 5) == 0) { | |
1509 | kfree(type); | |
c1c5413a SS |
1510 | return -ENODEV; |
1511 | } | |
b98a409b | 1512 | kfree(type); |
c1c5413a | 1513 | } |
9f27ee59 JF |
1514 | info = kzalloc(sizeof(*info), GFP_KERNEL); |
1515 | if (!info) { | |
1516 | xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure"); | |
1517 | return -ENOMEM; | |
1518 | } | |
1519 | ||
b70f5fa0 | 1520 | mutex_init(&info->mutex); |
3467811e | 1521 | spin_lock_init(&info->io_lock); |
9f27ee59 JF |
1522 | info->xbdev = dev; |
1523 | info->vdevice = vdevice; | |
bfe11d6d RPM |
1524 | INIT_LIST_HEAD(&info->grants); |
1525 | INIT_LIST_HEAD(&info->indirect_pages); | |
0a8704a5 | 1526 | info->persistent_gnts_c = 0; |
9f27ee59 JF |
1527 | info->connected = BLKIF_STATE_DISCONNECTED; |
1528 | INIT_WORK(&info->work, blkif_restart_queue); | |
1529 | ||
9f27ee59 JF |
1530 | /* Front end dir is a number, which is used as the id. */ |
1531 | info->handle = simple_strtoul(strrchr(dev->nodename, '/')+1, NULL, 0); | |
a1b4b12b | 1532 | dev_set_drvdata(&dev->dev, info); |
9f27ee59 | 1533 | |
9f27ee59 JF |
1534 | return 0; |
1535 | } | |
1536 | ||
4246a0b6 | 1537 | static void split_bio_end(struct bio *bio) |
402b27f9 RPM |
1538 | { |
1539 | struct split_bio *split_bio = bio->bi_private; | |
1540 | ||
402b27f9 RPM |
1541 | if (atomic_dec_and_test(&split_bio->pending)) { |
1542 | split_bio->bio->bi_phys_segments = 0; | |
4246a0b6 CH |
1543 | split_bio->bio->bi_error = bio->bi_error; |
1544 | bio_endio(split_bio->bio); | |
402b27f9 RPM |
1545 | kfree(split_bio); |
1546 | } | |
1547 | bio_put(bio); | |
1548 | } | |
9f27ee59 JF |
1549 | |
1550 | static int blkif_recover(struct blkfront_info *info) | |
1551 | { | |
1552 | int i; | |
402b27f9 | 1553 | struct request *req, *n; |
9f27ee59 | 1554 | struct blk_shadow *copy; |
402b27f9 RPM |
1555 | int rc; |
1556 | struct bio *bio, *cloned_bio; | |
1557 | struct bio_list bio_list, merge_bio; | |
1558 | unsigned int segs, offset; | |
1559 | int pending, size; | |
1560 | struct split_bio *split_bio; | |
1561 | struct list_head requests; | |
9f27ee59 JF |
1562 | |
1563 | /* Stage 1: Make a safe copy of the shadow state. */ | |
29d0b218 | 1564 | copy = kmemdup(info->shadow, sizeof(info->shadow), |
a144ff09 | 1565 | GFP_NOIO | __GFP_REPEAT | __GFP_HIGH); |
9f27ee59 JF |
1566 | if (!copy) |
1567 | return -ENOMEM; | |
9f27ee59 JF |
1568 | |
1569 | /* Stage 2: Set up free list. */ | |
1570 | memset(&info->shadow, 0, sizeof(info->shadow)); | |
86839c56 | 1571 | for (i = 0; i < BLK_RING_SIZE(info); i++) |
97e36834 | 1572 | info->shadow[i].req.u.rw.id = i+1; |
9f27ee59 | 1573 | info->shadow_free = info->ring.req_prod_pvt; |
86839c56 | 1574 | info->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff; |
9f27ee59 | 1575 | |
d50babbe | 1576 | rc = blkfront_gather_backend_features(info); |
402b27f9 RPM |
1577 | if (rc) { |
1578 | kfree(copy); | |
1579 | return rc; | |
1580 | } | |
1581 | ||
1582 | segs = info->max_indirect_segments ? : BLKIF_MAX_SEGMENTS_PER_REQUEST; | |
1583 | blk_queue_max_segments(info->rq, segs); | |
1584 | bio_list_init(&bio_list); | |
1585 | INIT_LIST_HEAD(&requests); | |
86839c56 | 1586 | for (i = 0; i < BLK_RING_SIZE(info); i++) { |
9f27ee59 | 1587 | /* Not in use? */ |
a945b980 | 1588 | if (!copy[i].request) |
9f27ee59 JF |
1589 | continue; |
1590 | ||
402b27f9 RPM |
1591 | /* |
1592 | * Get the bios in the request so we can re-queue them. | |
1593 | */ | |
1594 | if (copy[i].request->cmd_flags & | |
1595 | (REQ_FLUSH | REQ_FUA | REQ_DISCARD | REQ_SECURE)) { | |
1596 | /* | |
1597 | * Flush operations don't contain bios, so | |
1598 | * we need to requeue the whole request | |
1599 | */ | |
1600 | list_add(©[i].request->queuelist, &requests); | |
1601 | continue; | |
5ea42986 | 1602 | } |
402b27f9 RPM |
1603 | merge_bio.head = copy[i].request->bio; |
1604 | merge_bio.tail = copy[i].request->biotail; | |
1605 | bio_list_merge(&bio_list, &merge_bio); | |
1606 | copy[i].request->bio = NULL; | |
3bb8c98e | 1607 | blk_end_request_all(copy[i].request, 0); |
9f27ee59 JF |
1608 | } |
1609 | ||
1610 | kfree(copy); | |
1611 | ||
1612 | xenbus_switch_state(info->xbdev, XenbusStateConnected); | |
1613 | ||
3467811e | 1614 | spin_lock_irq(&info->io_lock); |
9f27ee59 JF |
1615 | |
1616 | /* Now safe for us to use the shared ring */ | |
1617 | info->connected = BLKIF_STATE_CONNECTED; | |
1618 | ||
9f27ee59 JF |
1619 | /* Kick any other new requests queued since we resumed */ |
1620 | kick_pending_request_queues(info); | |
1621 | ||
402b27f9 RPM |
1622 | list_for_each_entry_safe(req, n, &requests, queuelist) { |
1623 | /* Requeue pending requests (flush or discard) */ | |
1624 | list_del_init(&req->queuelist); | |
1625 | BUG_ON(req->nr_phys_segments > segs); | |
907c3eb1 | 1626 | blk_mq_requeue_request(req); |
402b27f9 | 1627 | } |
3467811e | 1628 | spin_unlock_irq(&info->io_lock); |
907c3eb1 | 1629 | blk_mq_kick_requeue_list(info->rq); |
9f27ee59 | 1630 | |
402b27f9 RPM |
1631 | while ((bio = bio_list_pop(&bio_list)) != NULL) { |
1632 | /* Traverse the list of pending bios and re-queue them */ | |
1633 | if (bio_segments(bio) > segs) { | |
1634 | /* | |
1635 | * This bio has more segments than what we can | |
1636 | * handle, we have to split it. | |
1637 | */ | |
1638 | pending = (bio_segments(bio) + segs - 1) / segs; | |
1639 | split_bio = kzalloc(sizeof(*split_bio), GFP_NOIO); | |
1640 | BUG_ON(split_bio == NULL); | |
1641 | atomic_set(&split_bio->pending, pending); | |
1642 | split_bio->bio = bio; | |
1643 | for (i = 0; i < pending; i++) { | |
1644 | offset = (i * segs * PAGE_SIZE) >> 9; | |
1645 | size = min((unsigned int)(segs * PAGE_SIZE) >> 9, | |
4f024f37 | 1646 | (unsigned int)bio_sectors(bio) - offset); |
402b27f9 RPM |
1647 | cloned_bio = bio_clone(bio, GFP_NOIO); |
1648 | BUG_ON(cloned_bio == NULL); | |
6678d83f | 1649 | bio_trim(cloned_bio, offset, size); |
402b27f9 RPM |
1650 | cloned_bio->bi_private = split_bio; |
1651 | cloned_bio->bi_end_io = split_bio_end; | |
1652 | submit_bio(cloned_bio->bi_rw, cloned_bio); | |
1653 | } | |
1654 | /* | |
1655 | * Now we have to wait for all those smaller bios to | |
1656 | * end, so we can also end the "parent" bio. | |
1657 | */ | |
1658 | continue; | |
1659 | } | |
1660 | /* We don't need to split this bio */ | |
1661 | submit_bio(bio->bi_rw, bio); | |
1662 | } | |
1663 | ||
9f27ee59 JF |
1664 | return 0; |
1665 | } | |
1666 | ||
1667 | /** | |
1668 | * We are reconnecting to the backend, due to a suspend/resume, or a backend | |
1669 | * driver restart. We tear down our blkif structure and recreate it, but | |
1670 | * leave the device-layer structures intact so that this is transparent to the | |
1671 | * rest of the kernel. | |
1672 | */ | |
1673 | static int blkfront_resume(struct xenbus_device *dev) | |
1674 | { | |
a1b4b12b | 1675 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
9f27ee59 JF |
1676 | int err; |
1677 | ||
1678 | dev_dbg(&dev->dev, "blkfront_resume: %s\n", dev->nodename); | |
1679 | ||
1680 | blkif_free(info, info->connected == BLKIF_STATE_CONNECTED); | |
1681 | ||
203fd61f | 1682 | err = talk_to_blkback(dev, info); |
402b27f9 RPM |
1683 | |
1684 | /* | |
1685 | * We have to wait for the backend to switch to | |
1686 | * connected state, since we want to read which | |
1687 | * features it supports. | |
1688 | */ | |
9f27ee59 JF |
1689 | |
1690 | return err; | |
1691 | } | |
1692 | ||
b70f5fa0 DS |
1693 | static void |
1694 | blkfront_closing(struct blkfront_info *info) | |
1695 | { | |
1696 | struct xenbus_device *xbdev = info->xbdev; | |
1697 | struct block_device *bdev = NULL; | |
1698 | ||
1699 | mutex_lock(&info->mutex); | |
1700 | ||
1701 | if (xbdev->state == XenbusStateClosing) { | |
1702 | mutex_unlock(&info->mutex); | |
1703 | return; | |
1704 | } | |
1705 | ||
1706 | if (info->gd) | |
1707 | bdev = bdget_disk(info->gd, 0); | |
1708 | ||
1709 | mutex_unlock(&info->mutex); | |
1710 | ||
1711 | if (!bdev) { | |
1712 | xenbus_frontend_closed(xbdev); | |
1713 | return; | |
1714 | } | |
1715 | ||
1716 | mutex_lock(&bdev->bd_mutex); | |
1717 | ||
7b32d104 | 1718 | if (bdev->bd_openers) { |
b70f5fa0 DS |
1719 | xenbus_dev_error(xbdev, -EBUSY, |
1720 | "Device in use; refusing to close"); | |
1721 | xenbus_switch_state(xbdev, XenbusStateClosing); | |
1722 | } else { | |
1723 | xlvbd_release_gendisk(info); | |
1724 | xenbus_frontend_closed(xbdev); | |
1725 | } | |
1726 | ||
1727 | mutex_unlock(&bdev->bd_mutex); | |
1728 | bdput(bdev); | |
1729 | } | |
9f27ee59 | 1730 | |
ed30bf31 LD |
1731 | static void blkfront_setup_discard(struct blkfront_info *info) |
1732 | { | |
1733 | int err; | |
ed30bf31 LD |
1734 | unsigned int discard_granularity; |
1735 | unsigned int discard_alignment; | |
5ea42986 | 1736 | unsigned int discard_secure; |
ed30bf31 | 1737 | |
1c8cad6c OH |
1738 | info->feature_discard = 1; |
1739 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1740 | "discard-granularity", "%u", &discard_granularity, | |
1741 | "discard-alignment", "%u", &discard_alignment, | |
1742 | NULL); | |
1743 | if (!err) { | |
1744 | info->discard_granularity = discard_granularity; | |
1745 | info->discard_alignment = discard_alignment; | |
1746 | } | |
1747 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1748 | "discard-secure", "%d", &discard_secure, | |
1749 | NULL); | |
1750 | if (!err) | |
1751 | info->feature_secdiscard = !!discard_secure; | |
ed30bf31 LD |
1752 | } |
1753 | ||
402b27f9 RPM |
1754 | static int blkfront_setup_indirect(struct blkfront_info *info) |
1755 | { | |
d50babbe | 1756 | unsigned int segs; |
402b27f9 RPM |
1757 | int err, i; |
1758 | ||
d50babbe | 1759 | if (info->max_indirect_segments == 0) |
402b27f9 | 1760 | segs = BLKIF_MAX_SEGMENTS_PER_REQUEST; |
d50babbe | 1761 | else |
402b27f9 | 1762 | segs = info->max_indirect_segments; |
402b27f9 | 1763 | |
86839c56 | 1764 | err = fill_grant_buffer(info, (segs + INDIRECT_GREFS(segs)) * BLK_RING_SIZE(info)); |
402b27f9 RPM |
1765 | if (err) |
1766 | goto out_of_memory; | |
1767 | ||
bfe11d6d RPM |
1768 | if (!info->feature_persistent && info->max_indirect_segments) { |
1769 | /* | |
1770 | * We are using indirect descriptors but not persistent | |
1771 | * grants, we need to allocate a set of pages that can be | |
1772 | * used for mapping indirect grefs | |
1773 | */ | |
86839c56 | 1774 | int num = INDIRECT_GREFS(segs) * BLK_RING_SIZE(info); |
bfe11d6d RPM |
1775 | |
1776 | BUG_ON(!list_empty(&info->indirect_pages)); | |
1777 | for (i = 0; i < num; i++) { | |
1778 | struct page *indirect_page = alloc_page(GFP_NOIO); | |
1779 | if (!indirect_page) | |
1780 | goto out_of_memory; | |
1781 | list_add(&indirect_page->lru, &info->indirect_pages); | |
1782 | } | |
1783 | } | |
1784 | ||
86839c56 | 1785 | for (i = 0; i < BLK_RING_SIZE(info); i++) { |
402b27f9 RPM |
1786 | info->shadow[i].grants_used = kzalloc( |
1787 | sizeof(info->shadow[i].grants_used[0]) * segs, | |
1788 | GFP_NOIO); | |
b7649158 | 1789 | info->shadow[i].sg = kzalloc(sizeof(info->shadow[i].sg[0]) * segs, GFP_NOIO); |
402b27f9 RPM |
1790 | if (info->max_indirect_segments) |
1791 | info->shadow[i].indirect_grants = kzalloc( | |
1792 | sizeof(info->shadow[i].indirect_grants[0]) * | |
1793 | INDIRECT_GREFS(segs), | |
1794 | GFP_NOIO); | |
1795 | if ((info->shadow[i].grants_used == NULL) || | |
b7649158 | 1796 | (info->shadow[i].sg == NULL) || |
402b27f9 RPM |
1797 | (info->max_indirect_segments && |
1798 | (info->shadow[i].indirect_grants == NULL))) | |
1799 | goto out_of_memory; | |
b7649158 | 1800 | sg_init_table(info->shadow[i].sg, segs); |
402b27f9 RPM |
1801 | } |
1802 | ||
1803 | ||
1804 | return 0; | |
1805 | ||
1806 | out_of_memory: | |
86839c56 | 1807 | for (i = 0; i < BLK_RING_SIZE(info); i++) { |
402b27f9 RPM |
1808 | kfree(info->shadow[i].grants_used); |
1809 | info->shadow[i].grants_used = NULL; | |
b7649158 RPM |
1810 | kfree(info->shadow[i].sg); |
1811 | info->shadow[i].sg = NULL; | |
402b27f9 RPM |
1812 | kfree(info->shadow[i].indirect_grants); |
1813 | info->shadow[i].indirect_grants = NULL; | |
1814 | } | |
bfe11d6d RPM |
1815 | if (!list_empty(&info->indirect_pages)) { |
1816 | struct page *indirect_page, *n; | |
1817 | list_for_each_entry_safe(indirect_page, n, &info->indirect_pages, lru) { | |
1818 | list_del(&indirect_page->lru); | |
1819 | __free_page(indirect_page); | |
1820 | } | |
1821 | } | |
402b27f9 RPM |
1822 | return -ENOMEM; |
1823 | } | |
1824 | ||
d50babbe BL |
1825 | /* |
1826 | * Gather all backend feature-* | |
1827 | */ | |
1828 | static int blkfront_gather_backend_features(struct blkfront_info *info) | |
1829 | { | |
1830 | int err; | |
1831 | int barrier, flush, discard, persistent; | |
1832 | unsigned int indirect_segments; | |
1833 | ||
1834 | info->feature_flush = 0; | |
1835 | ||
1836 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1837 | "feature-barrier", "%d", &barrier, | |
1838 | NULL); | |
1839 | ||
1840 | /* | |
1841 | * If there's no "feature-barrier" defined, then it means | |
1842 | * we're dealing with a very old backend which writes | |
1843 | * synchronously; nothing to do. | |
1844 | * | |
1845 | * If there are barriers, then we use flush. | |
1846 | */ | |
1847 | if (!err && barrier) | |
1848 | info->feature_flush = REQ_FLUSH | REQ_FUA; | |
1849 | /* | |
1850 | * And if there is "feature-flush-cache" use that above | |
1851 | * barriers. | |
1852 | */ | |
1853 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1854 | "feature-flush-cache", "%d", &flush, | |
1855 | NULL); | |
1856 | ||
1857 | if (!err && flush) | |
1858 | info->feature_flush = REQ_FLUSH; | |
1859 | ||
1860 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1861 | "feature-discard", "%d", &discard, | |
1862 | NULL); | |
1863 | ||
1864 | if (!err && discard) | |
1865 | blkfront_setup_discard(info); | |
1866 | ||
1867 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1868 | "feature-persistent", "%u", &persistent, | |
1869 | NULL); | |
1870 | if (err) | |
1871 | info->feature_persistent = 0; | |
1872 | else | |
1873 | info->feature_persistent = persistent; | |
1874 | ||
1875 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1876 | "feature-max-indirect-segments", "%u", &indirect_segments, | |
1877 | NULL); | |
1878 | if (err) | |
1879 | info->max_indirect_segments = 0; | |
1880 | else | |
1881 | info->max_indirect_segments = min(indirect_segments, | |
1882 | xen_blkif_max_segments); | |
1883 | ||
1884 | return blkfront_setup_indirect(info); | |
1885 | } | |
1886 | ||
9f27ee59 JF |
1887 | /* |
1888 | * Invoked when the backend is finally 'ready' (and has told produced | |
1889 | * the details about the physical device - #sectors, size, etc). | |
1890 | */ | |
1891 | static void blkfront_connect(struct blkfront_info *info) | |
1892 | { | |
1893 | unsigned long long sectors; | |
1894 | unsigned long sector_size; | |
7c4d7d71 | 1895 | unsigned int physical_sector_size; |
9f27ee59 JF |
1896 | unsigned int binfo; |
1897 | int err; | |
1898 | ||
1fa73be6 S |
1899 | switch (info->connected) { |
1900 | case BLKIF_STATE_CONNECTED: | |
1901 | /* | |
1902 | * Potentially, the back-end may be signalling | |
1903 | * a capacity change; update the capacity. | |
1904 | */ | |
1905 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, | |
1906 | "sectors", "%Lu", §ors); | |
1907 | if (XENBUS_EXIST_ERR(err)) | |
1908 | return; | |
1909 | printk(KERN_INFO "Setting capacity to %Lu\n", | |
1910 | sectors); | |
1911 | set_capacity(info->gd, sectors); | |
2def141e | 1912 | revalidate_disk(info->gd); |
1fa73be6 | 1913 | |
402b27f9 | 1914 | return; |
1fa73be6 | 1915 | case BLKIF_STATE_SUSPENDED: |
402b27f9 RPM |
1916 | /* |
1917 | * If we are recovering from suspension, we need to wait | |
1918 | * for the backend to announce it's features before | |
1919 | * reconnecting, at least we need to know if the backend | |
1920 | * supports indirect descriptors, and how many. | |
1921 | */ | |
1922 | blkif_recover(info); | |
9f27ee59 JF |
1923 | return; |
1924 | ||
b4dddb49 JF |
1925 | default: |
1926 | break; | |
1fa73be6 | 1927 | } |
9f27ee59 JF |
1928 | |
1929 | dev_dbg(&info->xbdev->dev, "%s:%s.\n", | |
1930 | __func__, info->xbdev->otherend); | |
1931 | ||
1932 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1933 | "sectors", "%llu", §ors, | |
1934 | "info", "%u", &binfo, | |
1935 | "sector-size", "%lu", §or_size, | |
1936 | NULL); | |
1937 | if (err) { | |
1938 | xenbus_dev_fatal(info->xbdev, err, | |
1939 | "reading backend fields at %s", | |
1940 | info->xbdev->otherend); | |
1941 | return; | |
1942 | } | |
1943 | ||
7c4d7d71 SB |
1944 | /* |
1945 | * physcial-sector-size is a newer field, so old backends may not | |
1946 | * provide this. Assume physical sector size to be the same as | |
1947 | * sector_size in that case. | |
1948 | */ | |
1949 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, | |
1950 | "physical-sector-size", "%u", &physical_sector_size); | |
1951 | if (err != 1) | |
1952 | physical_sector_size = sector_size; | |
1953 | ||
d50babbe | 1954 | err = blkfront_gather_backend_features(info); |
402b27f9 RPM |
1955 | if (err) { |
1956 | xenbus_dev_fatal(info->xbdev, err, "setup_indirect at %s", | |
1957 | info->xbdev->otherend); | |
1958 | return; | |
1959 | } | |
1960 | ||
7c4d7d71 SB |
1961 | err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size, |
1962 | physical_sector_size); | |
9f27ee59 JF |
1963 | if (err) { |
1964 | xenbus_dev_fatal(info->xbdev, err, "xlvbd_add at %s", | |
1965 | info->xbdev->otherend); | |
1966 | return; | |
1967 | } | |
1968 | ||
1969 | xenbus_switch_state(info->xbdev, XenbusStateConnected); | |
1970 | ||
1971 | /* Kick pending requests. */ | |
3467811e | 1972 | spin_lock_irq(&info->io_lock); |
9f27ee59 JF |
1973 | info->connected = BLKIF_STATE_CONNECTED; |
1974 | kick_pending_request_queues(info); | |
3467811e | 1975 | spin_unlock_irq(&info->io_lock); |
9f27ee59 JF |
1976 | |
1977 | add_disk(info->gd); | |
1d78d705 CL |
1978 | |
1979 | info->is_ready = 1; | |
9f27ee59 JF |
1980 | } |
1981 | ||
9f27ee59 JF |
1982 | /** |
1983 | * Callback received when the backend's state changes. | |
1984 | */ | |
203fd61f | 1985 | static void blkback_changed(struct xenbus_device *dev, |
9f27ee59 JF |
1986 | enum xenbus_state backend_state) |
1987 | { | |
a1b4b12b | 1988 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
9f27ee59 | 1989 | |
203fd61f | 1990 | dev_dbg(&dev->dev, "blkfront:blkback_changed to state %d.\n", backend_state); |
9f27ee59 JF |
1991 | |
1992 | switch (backend_state) { | |
9f27ee59 | 1993 | case XenbusStateInitWait: |
a9b54bb9 BL |
1994 | if (dev->state != XenbusStateInitialising) |
1995 | break; | |
8ab0144a BL |
1996 | if (talk_to_blkback(dev, info)) { |
1997 | kfree(info); | |
1998 | dev_set_drvdata(&dev->dev, NULL); | |
1999 | break; | |
2000 | } | |
2001 | case XenbusStateInitialising: | |
9f27ee59 | 2002 | case XenbusStateInitialised: |
b78c9512 NI |
2003 | case XenbusStateReconfiguring: |
2004 | case XenbusStateReconfigured: | |
9f27ee59 | 2005 | case XenbusStateUnknown: |
9f27ee59 JF |
2006 | break; |
2007 | ||
2008 | case XenbusStateConnected: | |
2009 | blkfront_connect(info); | |
2010 | break; | |
2011 | ||
36613717 DV |
2012 | case XenbusStateClosed: |
2013 | if (dev->state == XenbusStateClosed) | |
2014 | break; | |
2015 | /* Missed the backend's Closing state -- fallthrough */ | |
9f27ee59 | 2016 | case XenbusStateClosing: |
b70f5fa0 | 2017 | blkfront_closing(info); |
9f27ee59 JF |
2018 | break; |
2019 | } | |
2020 | } | |
2021 | ||
fa1bd359 | 2022 | static int blkfront_remove(struct xenbus_device *xbdev) |
9f27ee59 | 2023 | { |
fa1bd359 DS |
2024 | struct blkfront_info *info = dev_get_drvdata(&xbdev->dev); |
2025 | struct block_device *bdev = NULL; | |
2026 | struct gendisk *disk; | |
9f27ee59 | 2027 | |
fa1bd359 | 2028 | dev_dbg(&xbdev->dev, "%s removed", xbdev->nodename); |
9f27ee59 JF |
2029 | |
2030 | blkif_free(info, 0); | |
2031 | ||
fa1bd359 DS |
2032 | mutex_lock(&info->mutex); |
2033 | ||
2034 | disk = info->gd; | |
2035 | if (disk) | |
2036 | bdev = bdget_disk(disk, 0); | |
2037 | ||
2038 | info->xbdev = NULL; | |
2039 | mutex_unlock(&info->mutex); | |
2040 | ||
2041 | if (!bdev) { | |
2042 | kfree(info); | |
2043 | return 0; | |
2044 | } | |
2045 | ||
2046 | /* | |
2047 | * The xbdev was removed before we reached the Closed | |
2048 | * state. See if it's safe to remove the disk. If the bdev | |
2049 | * isn't closed yet, we let release take care of it. | |
2050 | */ | |
2051 | ||
2052 | mutex_lock(&bdev->bd_mutex); | |
2053 | info = disk->private_data; | |
2054 | ||
d54142c7 DS |
2055 | dev_warn(disk_to_dev(disk), |
2056 | "%s was hot-unplugged, %d stale handles\n", | |
2057 | xbdev->nodename, bdev->bd_openers); | |
2058 | ||
7b32d104 | 2059 | if (info && !bdev->bd_openers) { |
fa1bd359 DS |
2060 | xlvbd_release_gendisk(info); |
2061 | disk->private_data = NULL; | |
0e345826 | 2062 | kfree(info); |
fa1bd359 DS |
2063 | } |
2064 | ||
2065 | mutex_unlock(&bdev->bd_mutex); | |
2066 | bdput(bdev); | |
9f27ee59 JF |
2067 | |
2068 | return 0; | |
2069 | } | |
2070 | ||
1d78d705 CL |
2071 | static int blkfront_is_ready(struct xenbus_device *dev) |
2072 | { | |
a1b4b12b | 2073 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
1d78d705 | 2074 | |
5d7ed20e | 2075 | return info->is_ready && info->xbdev; |
1d78d705 CL |
2076 | } |
2077 | ||
a63c848b | 2078 | static int blkif_open(struct block_device *bdev, fmode_t mode) |
9f27ee59 | 2079 | { |
13961743 DS |
2080 | struct gendisk *disk = bdev->bd_disk; |
2081 | struct blkfront_info *info; | |
2082 | int err = 0; | |
6e9624b8 | 2083 | |
2a48fc0a | 2084 | mutex_lock(&blkfront_mutex); |
6e9624b8 | 2085 | |
13961743 DS |
2086 | info = disk->private_data; |
2087 | if (!info) { | |
2088 | /* xbdev gone */ | |
2089 | err = -ERESTARTSYS; | |
2090 | goto out; | |
2091 | } | |
2092 | ||
2093 | mutex_lock(&info->mutex); | |
2094 | ||
2095 | if (!info->gd) | |
2096 | /* xbdev is closed */ | |
2097 | err = -ERESTARTSYS; | |
2098 | ||
2099 | mutex_unlock(&info->mutex); | |
2100 | ||
13961743 | 2101 | out: |
2a48fc0a | 2102 | mutex_unlock(&blkfront_mutex); |
13961743 | 2103 | return err; |
9f27ee59 JF |
2104 | } |
2105 | ||
db2a144b | 2106 | static void blkif_release(struct gendisk *disk, fmode_t mode) |
9f27ee59 | 2107 | { |
a63c848b | 2108 | struct blkfront_info *info = disk->private_data; |
7fd152f4 DS |
2109 | struct block_device *bdev; |
2110 | struct xenbus_device *xbdev; | |
2111 | ||
2a48fc0a | 2112 | mutex_lock(&blkfront_mutex); |
7fd152f4 DS |
2113 | |
2114 | bdev = bdget_disk(disk, 0); | |
7fd152f4 | 2115 | |
2f089cb8 FP |
2116 | if (!bdev) { |
2117 | WARN(1, "Block device %s yanked out from us!\n", disk->disk_name); | |
2118 | goto out_mutex; | |
2119 | } | |
acfca3c6 DS |
2120 | if (bdev->bd_openers) |
2121 | goto out; | |
2122 | ||
7fd152f4 DS |
2123 | /* |
2124 | * Check if we have been instructed to close. We will have | |
2125 | * deferred this request, because the bdev was still open. | |
2126 | */ | |
2127 | ||
2128 | mutex_lock(&info->mutex); | |
2129 | xbdev = info->xbdev; | |
2130 | ||
2131 | if (xbdev && xbdev->state == XenbusStateClosing) { | |
2132 | /* pending switch to state closed */ | |
d54142c7 | 2133 | dev_info(disk_to_dev(bdev->bd_disk), "releasing disk\n"); |
7fd152f4 DS |
2134 | xlvbd_release_gendisk(info); |
2135 | xenbus_frontend_closed(info->xbdev); | |
2136 | } | |
2137 | ||
2138 | mutex_unlock(&info->mutex); | |
2139 | ||
2140 | if (!xbdev) { | |
2141 | /* sudden device removal */ | |
d54142c7 | 2142 | dev_info(disk_to_dev(bdev->bd_disk), "releasing disk\n"); |
7fd152f4 DS |
2143 | xlvbd_release_gendisk(info); |
2144 | disk->private_data = NULL; | |
2145 | kfree(info); | |
9f27ee59 | 2146 | } |
7fd152f4 | 2147 | |
a4cc14ec | 2148 | out: |
dad5cf65 | 2149 | bdput(bdev); |
2f089cb8 | 2150 | out_mutex: |
2a48fc0a | 2151 | mutex_unlock(&blkfront_mutex); |
9f27ee59 JF |
2152 | } |
2153 | ||
83d5cde4 | 2154 | static const struct block_device_operations xlvbd_block_fops = |
9f27ee59 JF |
2155 | { |
2156 | .owner = THIS_MODULE, | |
a63c848b AV |
2157 | .open = blkif_open, |
2158 | .release = blkif_release, | |
597592d9 | 2159 | .getgeo = blkif_getgeo, |
8a6cfeb6 | 2160 | .ioctl = blkif_ioctl, |
9f27ee59 JF |
2161 | }; |
2162 | ||
2163 | ||
ec9c42ec | 2164 | static const struct xenbus_device_id blkfront_ids[] = { |
9f27ee59 JF |
2165 | { "vbd" }, |
2166 | { "" } | |
2167 | }; | |
2168 | ||
95afae48 DV |
2169 | static struct xenbus_driver blkfront_driver = { |
2170 | .ids = blkfront_ids, | |
9f27ee59 JF |
2171 | .probe = blkfront_probe, |
2172 | .remove = blkfront_remove, | |
2173 | .resume = blkfront_resume, | |
203fd61f | 2174 | .otherend_changed = blkback_changed, |
1d78d705 | 2175 | .is_ready = blkfront_is_ready, |
95afae48 | 2176 | }; |
9f27ee59 JF |
2177 | |
2178 | static int __init xlblk_init(void) | |
2179 | { | |
469738e6 LE |
2180 | int ret; |
2181 | ||
6e833587 | 2182 | if (!xen_domain()) |
9f27ee59 JF |
2183 | return -ENODEV; |
2184 | ||
86839c56 BL |
2185 | if (xen_blkif_max_ring_order > XENBUS_MAX_RING_PAGE_ORDER) { |
2186 | pr_info("Invalid max_ring_order (%d), will use default max: %d.\n", | |
2187 | xen_blkif_max_ring_order, XENBUS_MAX_RING_PAGE_ORDER); | |
2188 | xen_blkif_max_ring_order = 0; | |
2189 | } | |
2190 | ||
51c71a3b | 2191 | if (!xen_has_pv_disk_devices()) |
b9136d20 IM |
2192 | return -ENODEV; |
2193 | ||
9f27ee59 JF |
2194 | if (register_blkdev(XENVBD_MAJOR, DEV_NAME)) { |
2195 | printk(KERN_WARNING "xen_blk: can't get major %d with name %s\n", | |
2196 | XENVBD_MAJOR, DEV_NAME); | |
2197 | return -ENODEV; | |
2198 | } | |
2199 | ||
73db144b | 2200 | ret = xenbus_register_frontend(&blkfront_driver); |
469738e6 LE |
2201 | if (ret) { |
2202 | unregister_blkdev(XENVBD_MAJOR, DEV_NAME); | |
2203 | return ret; | |
2204 | } | |
2205 | ||
2206 | return 0; | |
9f27ee59 JF |
2207 | } |
2208 | module_init(xlblk_init); | |
2209 | ||
2210 | ||
5a60d0cd | 2211 | static void __exit xlblk_exit(void) |
9f27ee59 | 2212 | { |
8605067f JB |
2213 | xenbus_unregister_driver(&blkfront_driver); |
2214 | unregister_blkdev(XENVBD_MAJOR, DEV_NAME); | |
2215 | kfree(minors); | |
9f27ee59 JF |
2216 | } |
2217 | module_exit(xlblk_exit); | |
2218 | ||
2219 | MODULE_DESCRIPTION("Xen virtual block device frontend"); | |
2220 | MODULE_LICENSE("GPL"); | |
2221 | MODULE_ALIAS_BLOCKDEV_MAJOR(XENVBD_MAJOR); | |
d2f0c52b | 2222 | MODULE_ALIAS("xen:vbd"); |
4f93f09b | 2223 | MODULE_ALIAS("xenblk"); |